Limiting simultaneous connections

If monitoring is enabled (p4 configure set monitor=1 or higher), you can set the server.maxcommands configurable to limit the number of simultaneous command requests that the service will attempt to handle.

Ideally, this value should be set both:

  • low enough to detect a runaway script or denial of service attack before the underlying hardware resources are exhausted

  • high enough to maintain a substantial margin of safety between the typical average number of connections and your site’s peak activity.

If P4LOG is set, the server log contain lines of the form:

Server is now using nnn active threads.

You can use the server log to determine what levels of activity are typical for your site. Set server.maxcommands to a value higher than your anticipated peak activity. We recommend at least 200% to 500% higher.

Commands that super and operator users can always run

Starting in 2019.1, if a problem occurs with server.maxcommands, users with the access level of super, or the user type of operator (see p4 user), can still run the following commands to diagnose the problem.

  • p4 admin

  • p4 configure, p4 counter, p4 counters

  • p4 group, p4 groups

  • p4 help, p4 help-graph

  • p4 info

  • p4 journals

  • p4 lockstat, p4 login, p4 login2, p4 logout, p4 logtail

  • p4 monitor

  • p4 protect, p4 protects, p4 pull

  • p4 server, p4 servers

  • p4 user, p4 users

To disable the super and operator users from having this capability, see the server.maxcommands.allow configurable.