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Date Posted: 05/05/2012

How to save parameter value to other parameter in LoadRunner? "How to save parameter value to other parameter in LoadRunner?". OK, there is a simple solution. To save parameter value to other parameter you have to: Evalu...  

 
 
Date Posted: 05/05/2012

  Problem Description: How to convert a parameter to an integer Solution: Use the atoi function To convert a parameter to integer: 1. Covert the parameter to a string using lr_eval_string. Example: lr_eval_string(...  

 
 
3

How many Vusers can run on a given computer
There are several factors that can affect the scalability of a script, and the number of Vusers that can be run, it is not always possible to determine the hardware requirements to run a given number of Vusers.

Solution: Determining the number of Vusers that can run on a Load Generator
In order to determine the number of Vusers that can be run on a given amount of hardware a few issues should be analyzed. Because there are several factors that can affect the scalability of a script it is not always possible to determine the hardware requirements to run an exact number of Vusers. The best approach is to run some tests to verify empirically the resource requirements of the specific scripts being used during a test.

The primary factors affecting the script execution are Memory and CPU Utilization. Other factors such as Network Bandwidth and Hard Disk speed can become factors but in virtually all cases the core issue will be Memory and CPU related.

In order to determine the number of Vusers that will run on a given Load Generator machine it is best to run some tests from the LoadRunner Controller. Create a scenario using the scripts in question where they are run on a remote Load Generator using a slow ramp up of Vusers. During this process monitor the Load Generator to see what Memory and CPU resources are used as the load is increased.

Note: In this case, the "load" that is being talked about is the client side processing load on the Load Generator machine itself and not the load on the Server (which is what is normally measured during an actual load test).
Using this method an accurate estimation may be made about how many Vusers can be run on that machine. Also some extrapolation may be done to determine additional hardware requirements for additional Vusers.

It is also wise to monitor the Load Generator machines during the actual test to ensure they are not a bottleneck in the test (as that would invalidate the test results anyway).
Some rules of thumb for monitoring load would be

• CPU usage should stay below ~80-90% continuous usage.
• Memory usage should stay within the physical limits of the machines memory.

This means that the "Commit Charge Total" should be less than the "Physical Memory Total" which will ensures that minimal paging is done to simulate physical memory.

Some additional notes regarding other factors relating to Vuser performance
Run-Time Settings That Affect Number of Vusers

When a test is run, the Controller launches a process called mmdrv.exe to actually run the Vusers. Normally Vusers are run as "threads" inside this process. This option can be changed in the Run-Time Settings under the "General" tab. Running Vusers as threads has the advantage of running multiple Vuser threads per mmdrv.exe driver process, which is more memory efficient than running each Vuser in its own driver process (as a "process"). In some circumstances (usually for stability), it can be desirable to run each Vuser in its own mmdrv.exe process. The key disadvantage to this method is that more Memory and CPU will be used as numerous mmdrv.exe processes are launched.

If you have a version that is prior to LaodRunner7.6, in addition to le to set the Vusers to run as either a process or a thread it is also possible to change the number of threads that will run in each mmdrv.exe process. This option can be changed in Tools -> [Expert Mode] Options under the Agent tab. Here there is a setting called "Max threads for Driver." This setting is by default 50 for most Vuser types. This is an adequate setting for most cases. If desired, the number can be changed, usually setting a lower number would be preferred to have some additional stability of Vusers (as fewer Vusers share memory address space). If one mmdrv.exe process crashes during the test run it will only affect those number of Vusers that it is controlling.

Windows NT and Windows 2000 Application Performance Boost Settings
If a another application like a screensaver, disk defragmenter, or other utility executes on the Load Generator during a scenario execution the Vusers may run slower, time out, etc.
Windows NT and Windows 2000 have settings affecting how programs are assigned time to the CPU which can affect performance. Ideally no other utilities are running during the test run to interfere. If necessary, changes can be made to the System Performance properties that can help the Vusers run at peak performance.

If your Load Generator machine is Windows 2000, configure the following to improve performance and run more Virtual Users per machine:
In the Control Panel Systems dialog box, click the Advanced tab, and make sure that the Background Services option is selected in the Performance Option section.
In Windows NT the same setting can be made in the Application Performance section of the Performance Option in the System Properties. Set Performance boost to "None."

How Many Vusers Can Run On A Given Computer
Date Posted: 05/05/2012

How many Vusers can run on a given computer There are several factors that can affect the scalability of a script, and the number of Vusers that can be run, it is not always possible to determine the hardware requirements to run a given number o...  

 
 
4
part of Hypertext Transfer Protocol -- HTTP/1.1
RFC 2616 Fielding, et al.

10 Status Code Definitions

Each Status-Code is described below, including a description of which method(s) it can follow and any metainformation required in the response.

10.1 Informational 1xx

This class of status code indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line. There are no required headers for this class of status code. Since HTTP/1.0 did not define any 1xx status codes, servers MUST NOT send a 1xx response to an HTTP/1.0 client except under experimental conditions.

A client MUST be prepared to accept one or more 1xx status responses prior to a regular response, even if the client does not expect a 100 (Continue) status message. Unexpected 1xx status responses MAY be ignored by a user agent.

Proxies MUST forward 1xx responses, unless the connection between the proxy and its client has been closed, or unless the proxy itself requested the generation of the 1xx response. (For example, if a

proxy adds a "Expect: 100-continue" field when it forwards a request, then it need not forward the corresponding 100 (Continue) response(s).)

10.1.1 100 Continue

The client SHOULD continue with its request. This interim response is used to inform the client that the initial part of the request has been received and has not yet been rejected by the server. The client SHOULD continue by sending the remainder of the request or, if the request has already been completed, ignore this response. The server MUST send a final response after the request has been completed. See section 8.2.3 for detailed discussion of the use and handling of this status code.

10.1.2 101 Switching Protocols

The server understands and is willing to comply with the client's request, via the Upgrade message header field (section 14.42), for a change in the application protocol being used on this connection. The server will switch protocols to those defined by the response's Upgrade header field immediately after the empty line which terminates the 101 response.

The protocol SHOULD be switched only when it is advantageous to do so. For example, switching to a newer version of HTTP is advantageous over older versions, and switching to a real-time, synchronous protocol might be advantageous when delivering resources that use such features.

10.2 Successful 2xx

This class of status code indicates that the client's request was successfully received, understood, and accepted.

10.2.1 200 OK

The request has succeeded. The information returned with the response is dependent on the method used in the request, for example:

GET an entity corresponding to the requested resource is sent in the response;

HEAD the entity-header fields corresponding to the requested resource are sent in the response without any message-body;

POST an entity describing or containing the result of the action;

TRACE an entity containing the request message as received by the end server.

10.2.2 201 Created

The request has been fulfilled and resulted in a new resource being created. The newly created resource can be referenced by the URI(s) returned in the entity of the response, with the most specific URI for the resource given by a Location header field. The response SHOULD include an entity containing a list of resource characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content-Type header field. The origin server MUST create the resource before returning the 201 status code. If the action cannot be carried out immediately, the server SHOULD respond with 202 (Accepted) response instead.

A 201 response MAY contain an ETag response header field indicating the current value of the entity tag for the requested variant just created, see section 14.19.

10.2.3 202 Accepted

The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place. There is no facility for re-sending a status code from an asynchronous operation such as this.

The 202 response is intentionally non-committal. Its purpose is to allow a server to accept a request for some other process (perhaps a batch-oriented process that is only run once per day) without requiring that the user agent's connection to the server persist until the process is completed. The entity returned with this response SHOULD include an indication of the request's current status and either a pointer to a status monitor or some estimate of when the user can expect the request to be fulfilled.

10.2.4 203 Non-Authoritative Information

The returned metainformation in the entity-header is not the definitive set as available from the origin server, but is gathered from a local or a third-party copy. The set presented MAY be a subset or superset of the original version. For example, including local annotation information about the resource might result in a superset of the metainformation known by the origin server. Use of this response code is not required and is only appropriate when the response would otherwise be 200 (OK).

10.2.5 204 No Content

The server has fulfilled the request but does not need to return an entity-body, and might want to return updated metainformation. The response MAY include new or updated metainformation in the form of entity-headers, which if present SHOULD be associated with the requested variant.

If the client is a user agent, it SHOULD NOT change its document view from that which caused the request to be sent. This response is primarily intended to allow input for actions to take place without causing a change to the user agent's active document view, although any new or updated metainformation SHOULD be applied to the document currently in the user agent's active view.

The 204 response MUST NOT include a message-body, and thus is always terminated by the first empty line after the header fields.

10.2.6 205 Reset Content

The server has fulfilled the request and the user agent SHOULD reset the document view which caused the request to be sent. This response is primarily intended to allow input for actions to take place via user input, followed by a clearing of the form in which the input is given so that the user can easily initiate another input action. The response MUST NOT include an entity.

10.2.7 206 Partial Content

The server has fulfilled the partial GET request for the resource. The request MUST have included a Range header field (section 14.35) indicating the desired range, and MAY have included an If-Range header field (section 14.27) to make the request conditional.

The response MUST include the following header fields:

      - Either a Content-Range header field (section 14.16) indicating
        the range included with this response, or a multipart/byteranges
        Content-Type including Content-Range fields for each part. If a
        Content-Length header field is present in the response, its
        value MUST match the actual number of OCTETs transmitted in the
        message-body.
      - Date
      - ETag and/or Content-Location, if the header would have been sent
        in a 200 response to the same request
      - Expires, Cache-Control, and/or Vary, if the field-value might
        differ from that sent in any previous response for the same
        variant

If the 206 response is the result of an If-Range request that used a strong cache validator (see section 13.3.3), the response SHOULD NOT include other entity-headers. If the response is the result of an If-Range request that used a weak validator, the response MUST NOT include other entity-headers; this prevents inconsistencies between cached entity-bodies and updated headers. Otherwise, the response MUST include all of the entity-headers that would have been returned with a 200 (OK) response to the same request.

A cache MUST NOT combine a 206 response with other previously cached content if the ETag or Last-Modified headers do not match exactly, see 13.5.4.

A cache that does not support the Range and Content-Range headers MUST NOT cache 206 (Partial) responses.

10.3 Redirection 3xx

This class of status code indicates that further action needs to be taken by the user agent in order to fulfill the request. The action required MAY be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A client SHOULD detect infinite redirection loops, since such loops generate network traffic for each redirection.

      Note: previous versions of this specification recommended a
      maximum of five redirections. Content developers should be aware
      that there might be clients that implement such a fixed
      limitation.

10.3.1 300 Multiple Choices

The requested resource corresponds to any one of a set of representations, each with its own specific location, and agent- driven negotiation information (section 12) is being provided so that the user (or user agent) can select a preferred representation and redirect its request to that location.

Unless it was a HEAD request, the response SHOULD include an entity containing a list of resource characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content- Type header field. Depending upon the format and the capabilities of

the user agent, selection of the most appropriate choice MAY be performed automatically. However, this specification does not define any standard for such automatic selection.

If the server has a preferred choice of representation, it SHOULD include the specific URI for that representation in the Location field; user agents MAY use the Location field value for automatic redirection. This response is cacheable unless indicated otherwise.

10.3.2 301 Moved Permanently

The requested resource has been assigned a new permanent URI and any future references to this resource SHOULD use one of the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the Request-URI to one or more of the new references returned by the server, where possible. This response is cacheable unless indicated otherwise.

The new permanent URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s).

If the 301 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued.

      Note: When automatically redirecting a POST request after
      receiving a 301 status code, some existing HTTP/1.0 user agents
      will erroneously change it into a GET request.

10.3.3 302 Found

The requested resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the client SHOULD continue to use the Request-URI for future requests. This response is only cacheable if indicated by a Cache-Control or Expires header field.

The temporary URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s).

If the 302 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued.

      Note: RFC 1945 and RFC 2068 specify that the client is not allowed
      to change the method on the redirected request.  However, most
      existing user agent implementations treat 302 as if it were a 303
      response, performing a GET on the Location field-value regardless
      of the original request method. The status codes 303 and 307 have
      been added for servers that wish to make unambiguously clear which
      kind of reaction is expected of the client.

10.3.4 303 See Other

The response to the request can be found under a different URI and SHOULD be retrieved using a GET method on that resource. This method exists primarily to allow the output of a POST-activated script to redirect the user agent to a selected resource. The new URI is not a substitute reference for the originally requested resource. The 303 response MUST NOT be cached, but the response to the second (redirected) request might be cacheable.

The different URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s).

      Note: Many pre-HTTP/1.1 user agents do not understand the 303
      status. When interoperability with such clients is a concern, the
      302 status code may be used instead, since most user agents react
      to a 302 response as described here for 303.

10.3.5 304 Not Modified

If the client has performed a conditional GET request and access is allowed, but the document has not been modified, the server SHOULD respond with this status code. The 304 response MUST NOT contain a message-body, and thus is always terminated by the first empty line after the header fields.

The response MUST include the following header fields:

      - Date, unless its omission is required by section 14.18.1

If a clockless origin server obeys these rules, and proxies and clients add their own Date to any response received without one (as already specified by [RFC 2068], section 14.19), caches will operate correctly.

      - ETag and/or Content-Location, if the header would have been sent
        in a 200 response to the same request
      - Expires, Cache-Control, and/or Vary, if the field-value might
        differ from that sent in any previous response for the same
        variant

If the conditional GET used a strong cache validator (see section 13.3.3), the response SHOULD NOT include other entity-headers. Otherwise (i.e., the conditional GET used a weak validator), the response MUST NOT include other entity-headers; this prevents inconsistencies between cached entity-bodies and updated headers.

If a 304 response indicates an entity not currently cached, then the cache MUST disregard the response and repeat the request without the conditional.

If a cache uses a received 304 response to update a cache entry, the cache MUST update the entry to reflect any new field values given in the response.

10.3.6 305 Use Proxy

The requested resource MUST be accessed through the proxy given by the Location field. The Location field gives the URI of the proxy. The recipient is expected to repeat this single request via the proxy. 305 responses MUST only be generated by origin servers.

      Note: RFC 2068 was not clear that 305 was intended to redirect a
      single request, and to be generated by origin servers only.  Not
      observing these limitations has significant security consequences.

10.3.7 306 (Unused)

The 306 status code was used in a previous version of the specification, is no longer used, and the code is reserved.

10.3.8 307 Temporary Redirect

The requested resource resides temporarily under a different URI. Since the redirection MAY be altered on occasion, the client SHOULD continue to use the Request-URI for future requests. This response is only cacheable if indicated by a Cache-Control or Expires header field.

The temporary URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s) , since many pre-HTTP/1.1 user agents do not understand the 307 status. Therefore, the note SHOULD contain the information necessary for a user to repeat the original request on the new URI.

If the 307 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued.

10.4 Client Error 4xx

The 4xx class of status code is intended for cases in which the client seems to have erred. Except when responding to a HEAD request, the server SHOULD include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. These status codes are applicable to any request method. User agents SHOULD display any included entity to the user.

If the client is sending data, a server implementation using TCP SHOULD be careful to ensure that the client acknowledges receipt of the packet(s) containing the response, before the server closes the input connection. If the client continues sending data to the server after the close, the server's TCP stack will send a reset packet to the client, which may erase the client's unacknowledged input buffers before they can be read and interpreted by the HTTP application.

10.4.1 400 Bad Request

The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.

10.4.2 401 Unauthorized

The request requires user authentication. The response MUST include a WWW-Authenticate header field (section 14.47) containing a challenge applicable to the requested resource. The client MAY repeat the request with a suitable Authorization header field (section 14.8). If the request already included Authorization credentials, then the 401 response indicates that authorization has been refused for those credentials. If the 401 response contains the same challenge as the prior response, and the user agent has already attempted authentication at least once, then the user SHOULD be presented the entity that was given in the response, since that entity might include relevant diagnostic information. HTTP access authentication is explained in "HTTP Authentication: Basic and Digest Access Authentication" [43].

10.4.3 402 Payment Required

This code is reserved for future use.

10.4.4 403 Forbidden

The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated. If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it SHOULD describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead.

10.4.5 404 Not Found

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address. This status code is commonly used when the server does not wish to reveal exactly why the request has been refused, or when no other response is applicable.

10.4.6 405 Method Not Allowed

The method specified in the Request-Line is not allowed for the resource identified by the Request-URI. The response MUST include an Allow header containing a list of valid methods for the requested resource.

10.4.7 406 Not Acceptable

The resource identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the accept headers sent in the request.

Unless it was a HEAD request, the response SHOULD include an entity containing a list of available entity characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content-Type header field. Depending upon the format and the capabilities of the user agent, selection of the most appropriate choice MAY be performed automatically. However, this specification does not define any standard for such automatic selection.

      Note: HTTP/1.1 servers are allowed to return responses which are
      not acceptable according to the accept headers sent in the
      request. In some cases, this may even be preferable to sending a
      406 response. User agents are encouraged to inspect the headers of
      an incoming response to determine if it is acceptable.

If the response could be unacceptable, a user agent SHOULD temporarily stop receipt of more data and query the user for a decision on further actions.

10.4.8 407 Proxy Authentication Required

This code is similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy. The proxy MUST return a Proxy-Authenticate header field (section 14.33) containing a challenge applicable to the proxy for the requested resource. The client MAY repeat the request with a suitable Proxy-Authorization header field (section 14.34). HTTP access authentication is explained in "HTTP Authentication: Basic and Digest Access Authentication" [43].

10.4.9 408 Request Timeout

The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time.

10.4.10 409 Conflict

The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request. The response body SHOULD include enough

information for the user to recognize the source of the conflict. Ideally, the response entity would include enough information for the user or user agent to fix the problem; however, that might not be possible and is not required.

Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the entity being PUT included changes to a resource which conflict with those made by an earlier (third-party) request, the server might use the 409 response to indicate that it can't complete the request. In this case, the response entity would likely contain a list of the differences between the two versions in a format defined by the response Content-Type.

10.4.11 410 Gone

The requested resource is no longer available at the server and no forwarding address is known. This condition is expected to be considered permanent. Clients with link editing capabilities SHOULD delete references to the Request-URI after user approval. If the server does not know, or has no facility to determine, whether or not the condition is permanent, the status code 404 (Not Found) SHOULD be used instead. This response is cacheable unless indicated otherwise.

The 410 response is primarily intended to assist the task of web maintenance by notifying the recipient that the resource is intentionally unavailable and that the server owners desire that remote links to that resource be removed. Such an event is common for limited-time, promotional services and for resources belonging to individuals no longer working at the server's site. It is not necessary to mark all permanently unavailable resources as "gone" or to keep the mark for any length of time -- that is left to the discretion of the server owner.

10.4.12 411 Length Required

The server refuses to accept the request without a defined Content- Length. The client MAY repeat the request if it adds a valid Content-Length header field containing the length of the message-body in the request message.

10.4.13 412 Precondition Failed

The precondition given in one or more of the request-header fields evaluated to false when it was tested on the server. This response code allows the client to place preconditions on the current resource metainformation (header field data) and thus prevent the requested method from being applied to a resource other than the one intended.

10.4.14 413 Request Entity Too Large

The server is refusing to process a request because the request entity is larger than the server is willing or able to process. The server MAY close the connection to prevent the client from continuing the request.

If the condition is temporary, the server SHOULD include a Retry- After header field to indicate that it is temporary and after what time the client MAY try again.

10.4.15 414 Request-URI Too Long

The server is refusing to service the request because the Request-URI is longer than the server is willing to interpret. This rare condition is only likely to occur when a client has improperly converted a POST request to a GET request with long query information, when the client has descended into a URI "black hole" of redirection (e.g., a redirected URI prefix that points to a suffix of itself), or when the server is under attack by a client attempting to exploit security holes present in some servers using fixed-length buffers for reading or manipulating the Request-URI.

10.4.16 415 Unsupported Media Type

The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.

10.4.17 416 Requested Range Not Satisfiable

A server SHOULD return a response with this status code if a request included a Range request-header field (section 14.35), and none of the range-specifier values in this field overlap the current extent of the selected resource, and the request did not include an If-Range request-header field. (For byte-ranges, this means that the first- byte-pos of all of the byte-range-spec values were greater than the current length of the selected resource.)

When this status code is returned for a byte-range request, the response SHOULD include a Content-Range entity-header field specifying the current length of the selected resource (see section 14.16). This response MUST NOT use the multipart/byteranges content- type.

10.4.18 417 Expectation Failed

The expectation given in an Expect request-header field (see section 14.20) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could not be met by the next-hop server.

10.5 Server Error 5xx

Response status codes beginning with the digit "5" indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding to a HEAD request, the server SHOULD include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. User agents SHOULD display any included entity to the user. These response codes are applicable to any request method.

10.5.1 500 Internal Server Error

The server encountered an unexpected condition which prevented it from fulfilling the request.

10.5.2 501 Not Implemented

The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource.

10.5.3 502 Bad Gateway

The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting to fulfill the request.

10.5.4 503 Service Unavailable

The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the delay MAY be indicated in a Retry-After header. If no Retry-After is given, the client SHOULD handle the response as it would for a 500 response.

      Note: The existence of the 503 status code does not imply that a
      server must use it when becoming overloaded. Some servers may wish
      to simply refuse the connection.

10.5.5 504 Gateway Timeout

The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server specified by the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server (e.g. DNS) it needed to access in attempting to complete the request.

      Note: Note to implementors: some deployed proxies are known to
      return 400 or 500 when DNS lookups time out.

10.5.6 505 HTTP Version Not Supported

The server does not support, or refuses to support, the HTTP protocol version that was used in the request message. The server is indicating that it is unable or unwilling to complete the request using the same major version as the client, as described in section 3.1, other than with this error message. The response SHOULD contain an entity describing why that version is not supported and what other protocols are supported by that server.

 

HTTP STATUS CODES
Date Posted: 05/05/2012

part of Hypertext Transfer Protocol -- HTTP/1.1 RFC 2616 Fielding, et al. 10 Status Code Definitions Each Status-Code is described below, including a description of which method(s) it can follow and any metainformation required...  

 
 
5

HOW TO HANDLE ERRORS AND RE-SUBMITTING THE SAME  WEB_URL REQUEST

// Declare integers
int HTTP_rc, retry_count;

/*
* This section includes the page request statement and switches on the
* continue on error functionality, for this step only.
*/
for (retry_count = 0; retry_count < 5; retry_count++)
{
lr_start_transaction("Transaction_Name");

lr_continue_on_error(1);
web_url("Index.htm",
"URL=http://webpage.server.co.uk/cgi-bin/gen001_serverselect.dll",
"Resource=0",
"RecContentType=text/html",
"Referer=",
"Snapshot=t1.inf",
"Mode=HTML",
LAST);
lr_continue_on_error(0);

// Captures the HTTP_rc
HTTP_rc = web_get_int_property(HTTP_INFO_RETURN_CODE);

// Condition statement: if less than 400 end transaction and carry on with rest of script
if (HTTP_rc < 400)
{
lr_end_transaction("Transaction_Name", LR_PASS);
lr_log_message("Index page displayed after %i attempts", retry_count +1);
break;
}

/*
* Condition statement: if equals 503 and retry_count is less than 4, wait for 5secs
* before logging a message confirming that page is not available and what attempt you are on
* NOTE: HTTP 503 = Server is busy
*/
else if (HTTP_rc == 503 && retry_count < 4)
{
lr_end_transaction("Transaction_Name", LR_STOP);
sleep(5000);
lr_log_message("Index page not available, retrying attempt %i", retry_count +1);
continue;
}

/*
* Condition statement: End Transaction. If HTTP error equals 503, log a message confirming
* that the page is not available and what HTTP error you received, i.e. 404 (Page not found)
* Finally, the last line exits the current iteration and fails this iteration.
*/
else
{
lr_end_transaction("Transaction_Name", LR_FAIL);
if (HTTP_rc == 503) lr_log_message ("Index page not available, no retry attempts left");
else lr_error_message("Index page failed, HTTP error %i received", HTTP_rc);
lr_exit(LR_EXIT_ITERATION_AND_CONTINUE, LR_FAIL);
}

}

How To Handle Erro And Re-submiting The Same Web_URL_Request
Date Posted: 05/05/2012

HOW TO HANDLE ERRORS AND RE-SUBMITTING THE SAME  WEB_URL REQUEST // Declare integers int HTTP_rc, retry_count; /* * This section includes the page request statement and switches on the * continue on error functionality, for this...  

 
 
Date Posted: 05/05/2012

Std Deviation, What formula does LoadRunner use?  If you guys understand :) I am happy..if u didn't understand about the explanation .just ignore don't ask me :P standard deviation = square root of variance variance is&nbs...  

 
 
Date Posted: 05/04/2012

The web_find function searches an HTML page for a specified text string. This function differs from the web_reg_find function, in that it is limited to HTML-based scripts (see Recording Options > Recording tab). This functio...  

 
 
8
  • Network
  • Network Interface: Bytes Received/sec
  • Network Interface: Bytes Sent/sec
  • Processors
  • Processor: % Processor Time
  • Processor: % Interrupt Time
  • Processor: % Privileged Time
  • System: Processor Queue Length
  • System: Context Switches/sec
  • Memory
  • Memory: Available MBytes
  • Memory: Pages/sec
  • Process W3wp.exe
  • Process: Page Faults / sec
  • Process: Working Set
  • Process: Private Bytes
  • Process: Virtual Bytes
  • Process: Handle Count
  • ASP.NET
  • ASP.NET: Requests Current
  • ASP.NET: Requests Queued
  • ASP.NET: Requests Rejected
  • ASP.NET: Request Execution Time
  • ASP.NET: Requests Wait Time
  • ASP.NET Applications: Requests/Sec
  • ASP.NET Applications: Requests Executing
  • ASP.NET Applications: Requests In Application Queue
  • ASP.NET Applications: Requests Timed Out
  • ASP.NET Applications: Cache Total Hit Ratio
  • ASP.NET Applications: Cache API Hit Ratio
  • ASP.NET Applications: Output Cache Hit Ratio
  • ASP.NET Applications: Errors Total/sec
  • ASP.NET Applications: Pipeline Instance Count
  • .NET CLR Memory: % Time in GC
  • .NET CLR Memory: # Bytes in all Heaps
  • .NET CLR Memory: # of Pinned Objects
  • .NET CLR Memory :# Gen 0 Collections
  • .NET CLR Memory: # Gen 1 Collections
  • .NET CLR Memory: # Gen 2 Collections
  • .NET CLR Memory: Allocated Bytes/sec
  • .NET CLR Memory: Gen 0 heap size
  • .NET CLR Memory: Gen 1 heap size
  • .NET CLR Memory: Gen 2 heap size
  • .NET CLR Memory: Large Object Heap Size
  • .NET CLR Exceptions: # of Exceps Thrown /sec
  • .NET CLR LocksAndThreads: Contention Rate / sec
  • .NET CLR LocksAndThreads: Current Queue Length
  • .NET CLR Data: SqlClient: Current # pooled connections
  • .NET CLR Data: SqlClient: Total # failed connects
  • Web Service: Bytes Sent/sec
  • Web Service: Bytes Received/sec
  • Web Service: Current Connections
  • Web Service: ISAPI Extension Requests/sec
  • SQL Server Metrics
  • SQL Server: General Statistics: User Connections
  • SQL Server: General Statistics: Logins/sec
  • SQL Server: General Statistics: Logouts/sec
  • SQL Server: Access Methods: Index Searches/sec
  • SQL Server: Access Methods: Full Scans/sec
  • SQL Server: Access Methods: Page Splits/sec
  • SQL Server: Buffer Manager: Buffer cache hit ratio
  • SQL Server: Buffer Manager: Page Life Expectancy
  • SQL Server: Buffer Manager: Checkpoint pages/sec
  • SQL Server: Buffer Manager: Free pages
  • SQL Server: Buffer Manager:
  • SQL Server: Cache Manager: Cache Hit Ratio
  • SQL Server: Cache Manager: Cache Use Counts/sec
  • SQL Server: Databases: Transactions/sec
  • SQL Server: Databases: Active Transactions
  • SQL Server: Locks: Lock Requests/sec
  • SQL Server: Locks: Lock Timeouts/sec
  • SQL Server: Locks: Lock Waits/sec
  • SQL Server: Locks: Number of Deadlocks/sec
  • SQL Server: Locks: Average Wait Time (ms)
  • SQL Server: Latches: Average Latch Wait Time(ms)
  • SQL Server: Latches: Latch Waits/sec
  • SQL Server: Latches: Total Latch Wait Time(ms)
  • SQL Server: Memory Manager: Maximum Workspace Memory (Kb)
  • SQL Server: Memory Manager: Target Server Memory (Kb)
  • SQL Server: Memory Manager: Total Server Memory (Kb)
  • SQL Server: SQL Statistics: Batch Requests/sec
  • SQL Server: SQL Statistics: SQL Compilations/sec
  • SQL Server: SQL Statistics: SQL Re-compilations/sec
  • Disk I/O
  • PhysicalDisk: Avg. Disk Queue Length
  • PhysicalDisk: Avg. Disk Read Queue Length
  • PhysicalDisk: Avg. Disk Write Queue Length
  • PhysicalDisk: Avg. Disk sec/Read
  • PhysicalDisk: Avg. Disk sec/Transfer
  • PhysicalDisk: Avg. Disk Bytes/Transfer
  • PhysicalDisk: Disk Writes/sec
  • PhysicalDisk: % Disk Time
  • PhysicalDisk: Current Disk Queue Length
Load Runner Windows Counters That We Need To Measure For Perform
Date Posted: 05/04/2012

Network Network Interface: Bytes Received/sec Network Interface: Bytes Sent/sec Processors Processor: % Processor Time Processor: % Interrupt Time Processor: % Privileged Time System: Processor Queue L...  

 
 
9

Correlation? What’s that?

If you think correlation has something to do with the fit of data points to a function curve on a graph, and the word has no meaning to you in the context of LoadRunner then this document is for you. It explains what correlation in LoadRunner is, why you have to do it, how to do it, and what to do when it goes wrong. If this is the first time that you have used LoadRunner, or if you have been using it a little but are not a guru, then read on.

Introduction

 LoadRunner when recording a script simply listens to the client (browser) talking to the server (web server) and writes it all down. The complete transcript of everything that was said, the dates/time, content, requests and replies can be found in the Recording Log. (View-> Output Window-> Recording Log) The script is sort of an easier to read version of this. The main difference is that the script only contains the client’s communication.

If you imagine that LoadRunner is an impersonator pretending to be the client (browser) the script is LoadRunner’s note that tell it what to say to the server to successfully fool it. We want the server to believe that LoadRunner is a real client, and so send it the information requested.

This script has the hard coded information of the original conversation (Browser session) that occurred between the client and server. This hard coded information may not be enough to fool the server during replay however. It may have to be correlated.

What is correlation?

 Correlation is where the script is modified so that some of the hard coded values in the script are no longer hard coded. Rather than have LoadRunner send the original value to the server, we may need to send different values.

For example, the original recorded script may have included the server sending the client a session identification number. Something to identify the client during that particular session. This session ID was hard coded into the script during recording.

 During replay, the server will send LoadRunner a new session ID. We need to capture this value, and incorporate it into the script so we can send it back to the server to correctly identify ourselves for this new session. If we leave the script unmodified, we will send the old hard coded session ID to the server. The server will look at it and think it invalid, or unknown, and so will not send us the pages we have requested. LoadRunner will not have successfully fooled the server into believing it is a client.

Correlation is the capturing of dynamic values passed from the server to the client and back. We save this captured value into a LoadRunner parameter, and then use this parameter in the script in place of the original value. During replay, LoadRunner will now listen to what the server sends to it, and when it makes requests of the server, send this new, valid value back to the server. Thus fooling the server into believing it is talking to a real client.

 Why do I have to correlate?

 If you try to replay a script without correlating first, then most likely the script will fail. The requests it sends to the server will not be replied to. Either the session ID is invalid, so the server won’t allow you into the site, or it won’t allow you to create new records because they are the same as existing ones, or the server won’t understand your request because it isn’t what it is expecting.

Any value which changes every time you connect to the server is a candidate for correlation. A correlated script will send the server the information it is looking for, and so allow the script to replay. This will allow many Vusers to replay the script many times, and so place load on your server.

What errors mean I have to correlate?

 There are no specific errors that are associated with correlation, but there are errors that could be caused because a value hasn’t been correlated. For example, a session ID. If an invalid session ID is sent to a web server, how that server responds depends on the implementation of that server. It might send a page specifically stating the Session ID is invalid and ask you to log in again. It might send an HTTP 404 Page not found error because the requesting user didn’t have permissions for the specified page, and so the server couldn’t find the page.

 In general any error message returned from the server after LoadRunner makes a request that complains about permissions can point to a hard coded value that needs to be correlated.

 The tools (functions) used to correlate.

 In LoadRunner 7.X there four functions that you can use for correlation. A list of them, along with documentation and examples can be found in the on-line documentation. From VuGen, go to Help-> Function reference-> Contents-> Web and Wireless Vuser Functions-> Correlation Functions.

 The first two functions are essentially the same, and I will talk about then together. The third function, the web_save_reg_param function differs in implementation, and the parameters it takes, but does the same job, and is used in much the same way. The last function is associated with the first two, and isn’t directly a correlation function, but rather a LoadRunner setting. It will be talked about later in a different section.

 Web_create_html_param :-

 This is the standard correlation function in LoadRunner 6.X and 7.X. This function takes three parameters.

 web_create_html_param ( “Parameter Name”,  “Left Boundary”, “Right Boundary” );

 Each of these parameters is a pointer to a string. That means that if they are entered as literal text, they need to be enclosed in “quotes“. Each parameter is separated by a comma.

 Parameter Name:- This is the name of the parameter, or place holder variable that LoadRunner will save the captured value into. After successfully capturing the value, the parameter name is used in the script in place of the original value. LoadRunner will identify the parameter / placeholder, and substitute the captured value for the placeholder during replay. This name should have no spaces, but apart from that limitation, it is entirely up to you what name you give.

Left Boundary:- This is where we tell LoadRunner how to find the dynamic value that we are looking for. In the Left Boundary we specify the text that will appear to the left of the changing value.

 Right Boundary:- This is where we tell LoadRunner how to identify the end of the dynamic value we are looking for. Here we place the text that will appear after the value we are looking for.

web_create_html_param_ex

web_create_html_param_ex ( “Parameter Name”, “Left Boundary”, “Right Boundary”, “Instance”);

This function is the same as the web_create_html_param function, except it doesn’t look for the first instance of the boundaries, but rather the nth instance of those boundaries. The first three parameters are the same, name, left, right, the last parameter is a pointer to a string, so it must be enclosed in double quotes. It is the number of the occurrence. If you place the number one here (i.e. “1”) then the function behaves exactly as the web_create_html_param function. It looks for the first occurrence. If you put the number three here (i.e. “3”) it will look for the 3rd occurrence of the left and right boundaries, and place what appears in between into the parameter.

web_reg_save_param

web_reg_save_param ( “Parameter Name” , , LAST );

The first thing to note about this function as different from the web_create_html_param functions is that the number of parameters it takes can vary. The first one is still the name, but after that there are different attributes that can be used. These attributes can appear in any order because they contain within them what they are. For example, the attribute to identify the left boundary is “LB= followed by the text of the left boundary. I won’t be talking about all of the options for this function, they are listed in the documentation. Please have a look at it. (Help-> Function Reference)

The first parameter is the name, then the list of attributes or parameters, then the keyword LAST. This identifies the end of the function. The keyword is not enclosed in quotes, all parameters are. All parameters and keywords are separated by commas.

Identifying values to correlate.

So we have the tools, and we know why we need to use them, but how do we know what to use them on? What values in the script need to be correlated. The simplest answer is, “Any value that changes between sessions required for the script to replay.”

A hypothetical example. We are logging onto a web site. When we send the server our user name and password, it replies to us with a session ID that is good for that session. The session ID needs to be correlated for replay. We need to capture this value during replay to use in the script in place of the hard coded value.

To identify values to correlate, record the script, and save it. Open a new script, and record the same actions, and business process again. As much as possible, during recording, enter the same values in both scripts. For example, user ID, password, and fields and edit selections. Save the second script, and then run it with Extended log. (Vuser-> Run time settings-> Log-> Extended log. Check all three options)

Go to tools-> Compare with Vuser, and choose the first recorded script. WinDiff will open and display the two scripts side by side. Lines with differences in them will be highlighted in Yellow. Differences within the line, will be in red.

If WinDiff gives an error here, dismiss the error, WinDiff will be minimized in the task bar. Right click on it. Choose restore. Then go to File-> Select Files/Directories, and manually select the action sections for the two scripts.

Differences like "lr_think_time" can be ignored. They are load runner pacing functions, and don’t represent data sent to the server.

Locate the first difference and take note of it and search the script open in VuGen for that difference. That is the original value hard coded into the script that was different in the second script. Highlight it, and copy it.

Go to the Recording log, and place your cursor at the top. Hit Control F (Ctrl+F) to do a search and paste in the original value. We are looking for the first occurrence of this value in the recording log. If you don’t find the value in the recording log, check you are looking in the right scripts recording log. Remember you have two almost identical scripts here.

If you find the value, scroll up in the log, and make sure the value was sent as part of a response from the server. The first header you come across while looking up the script should be preference with a receiving response. This indicates that the value was sent by the server to the client. If the value first appears as part of a sending request, then the value originated on the client side, and doesn’t need to be correlated, but rather parameterized. That is a different topic all together. The response will have a comment before it that looks like this

*** [tid=640   Action1           2] Receiving response (10/8/200112:10:26)

So, we have a value that is different between subsequent recordings, it was sent from the server to the client. This value most likely needs to be correlated. If the value you were looking for doesn’t meet these criteria,

  1. Different between recordings
  2. Originated first on the server and sent to the client

It probably doesn’t need to be correlated.

Now that we know Why and What, How do we parameterize?

Step 1.

After confirming that the first occurrence was part of a received response from the server, we need to now figure out where to place the web_create_html_param( ) function. The web_create_html_param statement needs to go immediately before the request that fetched the dynamic value from the server. In order to find this request or URL in the script, we need to replay the script once with extended log and all the three options (In Vuser->Runtime Settings->Log) turned on.

In the recording log, pick up the text that is before the dynamic value. This text should remain constant no matter how many times you replay the script and highlight it and copy it. This is the text that will identify to LoadRunner where to find the start of the value we are capturing.

Now, go to the execution log and search for the text that you just copied from the recording log.

You should see a corresponding Action1.c() at the beginning of that line with a number in the brackets. That is the number of the line the script where you need to put the web_create_html_param( ) function. The function should go right above that line in the script.

So, add a couple of blank lines to your script before the function at that line, and then type in web_create_html_param(“UserSession”   but give it a name that means more to you than UserSession.

Step 2.

Go back to the execution log and highlight the text to the left of the dynamic value and copy it. This should be some of the same text we searched for in the Execution log.

The amount of text you highlight should be sufficient so that it is unique in this reply from the server. I would suggest copying as much as possible without copying any special characters. These show in the execution log as black squares, and the actual character they represent is uncertain. After selecting a boundary, go to the top of the Servers reply, and hit Ctrl+F and do a search for that boundary. You want to make certain what you have selected is the first occurrence in the servers reply. If it isn’t select more text to make it unique, or consider using the web_create_html_param_ex function or the ORD parameter or the web_reg_save_param function.

Once you have finalized the static text that represents the left boundary, copy it into the web_create_html_param (or web_reg_save_param) statement. If it contains any carriage returns, place it all on one line. If there are any “ in the text, place the escape character before it so LoadRunner doesn’t incorrectly think it is the end of the parameter, but rather a character to search for. For example, if the Left boundary was 'input type=hidden name=userSession value=' without the single quotes and we are using the web_create_html_param statement, then the function we have so far would be

Web_create_html_param(“UserSession”, “input type=hidden name=userSession value=”,

Step 3.

We are now going to tell LoadRunner how to identify the end of the value we are trying to capture. That is the right boundary of what we are looking for. Again look in the execution log and copy the static text that appears to the right of the dynamic value we are looking for. For example, lets say the execution log contained the following

… userSession value=75893.0884568651DQADHfApHDHfcDtccpfAttcf>…

Then the example so far to save the number into the parameter UserSession would be

web_create_html_param(“UserSession”, “input type=hidden name=userSession value=”, “>”);

In choosing a right boundary, make sure you choose enough static text to specify the end of the value. If the boundary you specify appears in the value you are trying to capture, then you will not capture the whole value.

Recap:-

That was a lot of looking through the recording and execution logs and checking of values. Lets just recap what we have done. We have identified a value that we think needs to be correlated. We then identified in the script where to place the statement that would ultimately capture and save the value into a parameter. We then placed the statement, and gave LoadRunner the text strings that appear on either side of the value we are looking for so that it can find it.

The flow of logic for this is, the correlation functions tells LoadRunner what to look for in the next set of replies from the server. LoadRunner makes a request of the server. The server replies. LoadRunner looks thorough the replies for the left and right boundaries. If it finds then, what is in-between is then saved to a parameter of the name specified.

Remember, the parameter can’t have a value till AFTER the next statement is executed. The correlation statement only tells LoadRunner what to look for. It doesn’t assign a value to the parameter. Assignment of a value to the parameter doesn’t happen till after LoadRunner makes a request of the server and looks in the reply. If you have in your script a case where a correlation statement is followed by a function that attempts to use the parameter, the statement is in the wrong place, and the script will fail.

This is always incorrect:-

web_create_html_param(…);

Web_submit (… {Parameter}…);

There needs to be in-between the two, the request of the server that causes it to reply with the value we are trying to capture.

Replacing the hard coded value in the script with the parameter.

Once we have created the parameter, the next step is to replace the hard coded occurrences with the parameter. Look through the script for the original value. Where you find it, delete out the value and replace it with the parameter. Note, only the value we want replaces is deleted. The characters around it remain.

i.e.

Change :                                                                   

             .....                                            .....userSession=75893.0884568651DQADHfApHDHfcDtccpfAttcf&username=test........

             .....                                                          

 

 To :                                                                       

             .....                                                          

             .....userSession={UserSession}&username=test........

             .....

At this point, you are ready to run the script to test if it works, or if it needs further correlation, or more work on this correlation.

Common errors when correlating.

When LoadRunner fails to find the boundaries for a web_create, it will print a warning message in the execution log like this:-

Warning: No match found for the requested parameter "Name". If the data you want to save exceeds 256 bytes, use web_set_max_html_param_len to increase the parameter size

Firstly, this is a warning not an error. There are times when you might want to use the web_create_html_param function for purposes other that correlation. These require the function to not cause an error, so this is a warning.

Secondly, the advice the warning message gives is good, but I recommend thinking about it first. Was the value you were trying to capture more than 256 characters long? In the above example it was only 20 characters long. Have a look at the recording log and see how long the original value is. Have a look at the second recording made earlier and see how long it was in that script. Turn on the extended log (Run-Time settings-> Log-> Extended log-> All data returned from server) and have a look at how long it is in the execution log. If at any time any of these values was close to being, say 200 characters, then yes, add a web_set_max_html_param_len statement to the start of the script to make the maximum longer than 256 characters. If all occurrences of the script were much shorter that the max parameter length then the problem is either the web_create_html_param is in the wrong place, or that the boundaries are incorrect. Go back and look at the boundaries that you have selected, look at the placement of the web_create_html_param function. Is it immediately before the statement that causes the server to reply with the data you are looking for?

The Parameter length is longer than the current maximum.

(The web_set_max_html_param_len function)

web_set_max_html_param_len ( “length” );

This statement tells LoadRunner to look for larger matches for the left and right parameter. When it finds the left boundary, it will look ahead the max parameter length for the right boundary. This setting is script wide, and takes effect from when it is executed. It only needs appear in the script once. Having LoadRunner look for longer matches uses up more memory, and CPU to search through the returned text from the server. For this reason, don’t set it too high, or you will be making your script less scalable. That is you will reduce the number of Vusers that can run it on a given machine. Try to have the maximum parameter length no more than 100 characters greater that what you are expecting.

Special cases for the boundaries:-

There are some special characters and cases when specifying the boundaries. Double quotes should be preceded by a so LoadRunner recognizes then as part of the string to look for. If your text includes any carriage returns, that are part of the http, and not just part of the wrap around in the recording log, these need to be specified as a character set. If the character is part of the text, it too needs to be preceded by a to indicate it is a literal.

Recording log                                     boundary parameters (left,                  right)

 

Value=”57685”                                   “Value=””                                          “””

 

Value_”item”value’7875’                 “Value_”item”value’                     “’”

 

Value=                                                            “Value= ””                                     “””

“7898756”

Debug help

Sometimes you want to print out the value that was assigned to a parameter. To do this, use the lr_eval_string function, and the lr_output_message function. For example, to print the value of the parameter to the execution log.

lr_output_message(“ Value Captured = %s", lr_eval_string("{Name}"));

If you find that the value being substituted is too long, too short, or completely wrong, printing out the value will help identify the changes you need to make to the correlation function. If you have extra characters at the start of the value, you need to add them to the end of the left boundary, if you have extra characters at the end of the parameter value, you need to add them to the start of the right boundary. If you are getting the wrong value all together, do searches in the recording log for the left boundary, and make sure that you have a unique boundary, and that LoadRunner isn’t picking up an earlier occurrence. You can then use the web_create_html_param_ex function, or add to the boundaries to make them unique.

CORRELATION IN LOADRUNNER
Date Posted: 05/04/2012

Correlation? What’s that? If you think correlation has something to do with the fit of data points to a function curve on a graph, and the word has no meaning to you in the context of LoadRunner then this document is for you. It explains...  

 
 
10Working With Citrix In Loadrunner
Date Posted: 05/04/2012

 
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