Showing entries 1 to 4
Displaying posts with tag: table_open_cache (reset)
Random Pauses In MySQL – File Handle Serialization

Last month, I blogged about a case involving InnoDB, where all threads acting on InnoDB tables completely stuck for about few hours doing nothing; until we found a way to[...]

Changing process.max-file-descriptor using 'ulimit -n' can cause MySQL to change table_open_cache value

Before I get into details here is the bottom line. If you start MySQL on Solaris as a non-root (ie, mysql) user and for some reason you need to adjust the file descriptor resource limit for the parent shell, never use 'ulimit -n'. This will set both the soft and hard limit and may cause MySQL to adjust the max_connections and table_open_cache configuration variables upon next startup.

Use either:

 ulimit -S -n 1024

or something like:

prctl -n process.max-file-descriptor -t basic -v  1024 -r -i process $$



The Details

The default 'basic' privilege value for the resource control process.max-file-descriptor is 256. This control represents the soft ulimit for file descriptors per process. The default 'privileged' privilege is set to 65535, which represents the hard ulimit. A non-root user can adjust the soft limit down or up to the hard limit. Unless it has PRIV_SYS_RESOURCE a …

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Changing process.max-file-descriptor using 'ulimit -n' can cause MySQL to change table_open_cache value

Before I get into details here is the bottom line. If you start MySQL on Solaris as a non-root (ie, mysql) user and for some reason you need to adjust the file descriptor resource limit for the parent shell, never use 'ulimit -n'. This will set both the soft and hard limit and may cause MySQL to adjust the max_connections and table_open_cache configuration variables upon next startup.

Use either:

 ulimit -S -n 1024

or something like:

prctl -n process.max-file-descriptor -t basic -v  1024 -r -i process $$



The Details

The default 'basic' privilege value for the resource control process.max-file-descriptor is 256. This control represents the soft ulimit for file descriptors per process. The default 'privileged' privilege is set to 65535, which represents the hard ulimit. A non-root user can adjust the soft limit down or up to the hard limit. Unless it has PRIV_SYS_RESOURCE a …

[Read more]
Changing process.max-file-descriptor using 'ulimit -n' can cause MySQL to change table_open_cache value

Before I get into details here is the bottom line. If you start MySQL on Solaris as a non-root (ie, mysql) user and for some reason you need to adjust the file descriptor resource limit for the parent shell, never use 'ulimit -n'. This will set both the soft and hard limit and may cause MySQL to adjust the max_connections and table_open_cache configuration variables upon next startup.

Use either:

 ulimit -S -n 1024

or something like:

prctl -n process.max-file-descriptor -t basic -v  1024 -r -i process $$



The Details

The default 'basic' privilege value for the resource control process.max-file-descriptor is 256. This control represents the soft ulimit for file descriptors per process. The default 'privileged' privilege is set to 65535, which represents the hard ulimit. A non-root user can adjust the soft limit down or up to the hard limit. Unless it has PRIV_SYS_RESOURCE a …

[Read more]
Showing entries 1 to 4