All threads are currently busy solution

January 22, 2011 Advanced Performance Tester Skills

1. Development Knowledge:

N at least a good command of an object-oriented programming language (such as C #), familiar with 2 or more languages (specifically what languages need to be familiar with, you can make decisions based on the project situation).

N at least two scripting languages, mastering VBScript under the Windows platform (easy to learn, practical for testing), mastering Perl under the Linux platform.

2. Database knowledge:

N at least a good command of database-related performance tuning and management, to intermediate DBA level (the recommended Oracle database), to understand MySQL or SQL Server database.

3. operating system:

N at least proficient in the Linux operating system performance tuning and management, to achieve intermediate system management level (recommended Redhat Linux operating system). Learn about other Unix operating systems

N Network Knowledge:

N familiar with the TCP/IP protocol,

4. Testing Knowledge:

N at least two performance test tools, one is Windows platform, the other is Linux platform: LoadRunner, Http_load and so on.

n familiar with the relevant test theory knowledge.

5. Software Engineering:

n Master UML, design pattern, development mode, etc. at least

6. Industry Knowledge:

N Understand the industry knowledge of the project

Description of the relevant knowledge will continue to add ...

Posted @ 2011-01-22 19:32 Small confused fairy reading (14) | Comments (0) | Edit

January 16, 2010 elearning Performance Test Summary Report elearning Performance Test Summary report I       Project situation  

Project name	Elearning
Tuning process	To locate an application that has no thread-safe code DBA navigates to SQL without binding variables and adds indexes to the database Increase the number of JBoss AJP connector threads Adjusting JVM Parameters Adjust DBCP Connection Pool parameters Increase log4j log threshold to reduce IO
Problem accumulation	Server hardware is adequate, but Web server layer error frequency is high when performance is satisfied
Final conclusion	The cost of adding HTTP headers, locating non thread-safe, and DBCP connection parameters is the most expensive. This performance testing and tuning involves a number of levels, positioning performance bottlenecks rely on the common knowledge accumulation, as long as the split module properly, positioning bottlenecks have patterns to follow. To troubleshoot whether a bottleneck is needed for DBA assistance in the database. In addition, Google is a first-rate helper when confronted with problems.
Resource consumption	Lasted 2 weeks

ii. problems and solutions in implementation Category I issues (resolved):

Number	Problem description	Solving method
1	The manual execution function succeeded, but the Vugen execution script server response returned 0 bytes	Use the sniffer ethereal to discover the differences between hand-executed and Vugen execution scripts, adding Web_add_auto_header ("Modeltype", "model"); Solve the problem, after consulting Neusoft development Engineer, server-side resolution input code has if ("Model". Equals (Webrequest.getheader ("Modeltype")) Judge
2	Contoller insufficient records for Param X into table to provide the vuser with unique data	Delete Root disk directory local settings/temp file, exclude interference
3	A server random error was detected while executing concurrently, confirming that there is no thread-safe code	In the client, the server side respectively uses the sniffer (fiddler, Ethereal, tcpdump) confirms the contract, the receipt package the condition, confirms that the contract is correct, the server HttpRequest receives the package also to be correct. So the program appears in the internal variable does not do thread synchronization
4	apache  error_log:  [ERROR] server reached maxclients setting, consid Er raising the maxclients setting	In httpd.conf add: startservers ten mins Pareservers Maxspareservers Serverlimit 3000 MaxClients 2000  Maxrequestsperchild 10000 KeepAliveTimeout   and restart httpd service
5	java.lang.OutOfMemoryError:PermGen space, Java.lang.OutOfMemoryErro R:unable to create new native	Adjust JVM, add heap, stack control, and other parameters. Final Run.conf:   java_opts=-xms1536m-xmx1536m -xx:permsize=512m-xx:maxpermsize=512m -xss256k -dsun.rmi.dgc.client.gcinterval=3600000-dsun.rmi.dgc.server.gcinterval=3600000- Dcom.sun.management.jmxremote.port=9999-dcom.sun.management.jmxremote.authenticate=false- Dcom.sun.management.jmxremote.ssl=false
6	JBoss Server.log has all threads are currently busy, waiting. Increase MaxThreads or check the servlet status	Apache forward http via mod_jk1.2 Request to JBoss. So modify Jboss-4.0.5.ga/server/default/deploy/server.xml Adjust AJP connector settings:   <!--A AJP 1.3 Connector on port 8009-->       <connector port= "8009" address= jboss.bind.address} "backlog=" 1200          maxthreads= "2100" minsparethreads= "maxsparethreads="          Emptysessionpath= "true" enablelookups= "false" redirectport= "8443"           protocol= "ajp/1.3"/>   Add file handles .bash_profile :  in linux  ulimit  -n  4096
7	ora-00020:maximum Number of processes (+) exceeded	& nbsp;  using Oracle Statspack and checking for wait event, no database blocking was found. Therefore, the location to the connection pool parameter improper configuration caused the exception. Change the Apache DBCP connection pool parameters to prevent connection leak. <set property= "removeabandoned" value= "true"/>                                   <set property= "Removeabandonedtimeout" value= "a"/>                                   <set property= "logabandoned" value= "true"/ >
8	Adjust log4j log level	In Jboss-4.0.5.ga/server/default/conf/log4j.xml Increase log output threshold: <param value= "ERROR"/>

 

Class II issues (unresolved):

Number	Problem description	Avoidance scheme
1

Category III Issues (Legacy):

Number	Problem description	Legacy reasons
1	Server hardware is adequate for performance scenarios, but the Web server layer applies a large number of code errors	has satisfied performance. It is recommended to use tools such as TPTP, Jprofiler or JRockit Mission control to locate hotspot methods.

third, technology development

Refer to the information used in the tuning:

1 Apache Tomcat Configuration Reference http://tomcat.apache.org/tomcat-5.5-doc/config/ajp.html

2 outofmemoryexceptionwhenredeploying http://wiki.jboss.org/wiki/Wiki.jsp?page=OutOfMemoryExceptionWhenRedeploying

3 Preventing DB Connection pool leaks

Http://tomcat.apache.org/tomcat-5.5-doc/jndi-datasource-examples-howto.html

4 Apache Performance Tuning

Http://httpd.apache.org/docs/2.0/misc/perf-tuning.html

5 Tuning Garbage Collection with the 5.0 Java[tm] Virtual Machine

Http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html

Posted @ 2010-01-16 15:36 Small confused fairy reading (1116) | Comments (0) | Edit