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  1. Documentation
  2. DOCS-11904

Docs for SERVER-33697: Provide sanity check on number of cached sessions


      Original Description


      No documentation summary in engineering ticket

      Engineering Ticket Description:

      Driver or application errors can result in an unbounded number of cached sessions, and that can result in performance degradation and eventually OOM. It would be useful to provide a sanity check, say at 1 M cached sessions, and warn or refuse further sessions when it is exceeded.

      Fix Implementation

      The commands that add new sessions to the cache are start_session_command, refresh_sessions_command and refresh_sessions_command_internal. These commands will now return false when the cache is full. The maximum number of sessions can be configured through an optional argument to the mongod command (maxSessions) and will default to 1M. LogicalSessionCacheImpl::_addToCache https://github.com/mongodb/mongo/blob/master/src/mongo/db/logical_session_cache_impl.cpp#L102  and LogicalSessionCacheImpl::startSession will now return a Status instead of void.



      Scope of changes (files that need work and how much)

      Impact to other docs outside of this product

      MVP (work and date?)

      Resources (e.g. Scope Docs, Invision)

            kay.kim@mongodb.com Kay Kim (Inactive)
            kay.kim@mongodb.com Kay Kim (Inactive)
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              5 years, 38 weeks, 1 day ago