Performance Testing and Engineering

In this blog, I’ll tell you how to load test the oracle database using loadrunner. There are different ways to achieve it and one simple way is writing SQL queries in vugen script. In this blog I’m going to tell how to connect to database, how to execute query and how to disconnect. I will be using lr_db functions to achieve this. Loadrunner help is very useful with details about lr_db functions. Connect to Oracle database: lr_db_connect("StepName=Connect",         "ConnectionString=Provider=OraOLEDB.Oracle; dbq=10.xx.xx.xx:1540; Data Source=XXXX; Persist Security Info=True; User ID=username; Password=password",         "ConnectionName=OracleDB",         "ConnectionType=OLEDB", LAST ); SQL statement: lr_db_executeSQLStatement("StepName=PerformQuery",                 "ConnectionName= ...

Here are the top 7 Command tools which are very useful to monitor and debug Linux System Performance which are frequently used command line to monitor Linux system performance. TOP - LINXU PROCESS MONITORING It display CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size, Process PID, User, Commands and much more. It also shows high memory and cpu utilization of a running processess. The top command is much userful for system administrator to monitor and take correct action when required. Let’s see top command in action. # top VMSTAT – VIRTUAL MEMORY STATISTICS Linux VmStat command used to display statistics of virtual memory, kernerl threads, disks, system processes, I/O blocks, interrupts, CPU activity and much more.  # vmstat TCPDUMP – NETWORK PACKET ANALYZER Tcpdump one of the most widely used command-line network packet analyzer or packets sniffer program that is used capture or filter TCP/IP packets that received or transferred on a...

Main causes of Out-Of-Memory Errors When there is no enough space to create a new object in heap JVM through a Out-of-memory errors before giving this error JVM surly runs garbage collector once to check for available memory which can be freed .The main causes for this error can be. It is possible that you have estimate less memory for your application for example your application need 2 Gb of memory but you have configured only 512 Mb so here you will get an OOME(Out-of-memory errors )  1.Due to Memoryleak :- Memory leak is responsible for decreasing the available memory for heap and can lead to out of memory error for more read What is a Memory Leak in java?  2.Memory fragmentation :- It is possible that there may be space in heap but it may be not contiguous . And heap needs compaction . Rearrange its memory. 3.Excess GC overhead :- Some JVM implementations, such as the Oracle HotSpot, will throw an out-of-memory error when GC overhead becomes too great. This...

The  web_set_max_html_param_len  function sets the maximum length of any HTML string which VuGen can retrieve and save in a parameter. The default value for the maximum length of a parameter that can be captured during correlation is 256 characters. To retrieve a string longer than 256 characters, use  web_set_max_html_param_len  to increase the maximum valid length. An attempt to save a string whose length exceeds the maximum length will fail

Here is step by step procedure for network virtualisation in truclient protocol http://community.hpe.com/t5/LoadRunner-and-Performance/New-to-Network-Virtualization-emulation-in-TruClient-Here-s-an/ba-p/6883204#.V5z5DPl97IU

Lr_set_debug_message – One of my favourite lr function in load runner. It is mainly useful when we are unable to find correlation value in a particular request. We usually use  Extended log -> Data Returned by Server  in Run-time Settings to get all the response in replay log. Sometimes the vugen will crash or becomes slow as the vugen is writing all the response to replay log. Extended Log in Run-time Settings If it crashes or taking long time to execute the script then it’s better to use lr_set_debug_message instead of using  Data Returned by Server . In the following example we have added data returned by server only to particular request. Example:   lr_set_debug_message   ( LR_MSG_CLASS_EXTENDED_LOG   |   LR_MSG_CLASS_FULL_TRACE ,   LR_SWITCH_ON );          web_ url ( "Bing" ,          " URL = http://www.bing.com/ " ,      ...

Types of Action files Vuser_init Action Vuser_end Vuser_init This is the first action that is executed by the vuser and it comes under the  init  section of the script. It is executed only once in the life cycle of a vuser. By life cycle we mean the time between the start and the stop of a vuser. Even if the vuser has multiple iterations to execute, the set of steps incorporated within this action file is executed only once. We cannot disable/delete vuser_init. Even if it does not contain any steps to execute, it has to be present. We can put those steps in vuser_init that need to be executed only once. E.g. a script that logs in the same user to an application and performs certain tasks, since the same user is logging in every time, login steps can be put in vuser_init. But it also depends on the business requirement whether we should include launch and login in vuser_init. If launch and login is to be observed for its performance then including them in vuser_i...