Anti-Virus Software
Continua CI invokes programs such as Subversion, Mercurial, Git, MSbuild etc that create or modify lots of files. Anti-virus software is known to cause major peformance problems with these programs, in particular, fille system write performance. This impacts on Repositories on the Server, when pulling down changes from the a remote repository, and Build performance on the agent Agent when syncing the workspace or cloning the Repository Cache onto the agent Agent machine, and when exporting the source to the Build workspace from the agentAgent's repository cache. In our testing with mercurial, a clone that took 2 minutes to complete with anti-virus disabled, took over 14 minutes to complete when Windows Security Essentials anti-virus was enabled.
AV software can also cause application errors, such as Access Denied, or File Not Found when invoking compilers and version control clients.
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If you are using the bundled Postgresql Database Engine, then you should also add a folder exclusion for C:\ProgramData\VSoft\ContinuaCI\PostgreSQLDB to avoid database errors (av software can cause read timeouts, and issues with backing up the database).
Note that some anti-virus software, even when folder exclusions are added, can cause increases in CPU and I/O usage.
Indexing Services
Windows Indexing Service can cause file locking issues, and the Server and Agent workspace folders should be excluded from the index, or the Index service disabled (it is of limited use in server environments).
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