Problem

Bundled Elasticsearch has certain dependencies on the kernel in Linux, i.e. number of open files and virtual memory settings.
Those parameters are not being checked during the Bitbucket startup but showing as a warnings in the logs of Elasticsearch afterwards:

[2020-03-25T10:32:25,291][WARN ][o.e.b.BootstrapChecks    ] [bitbucket_bundled]max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]

[2020-03-25T11:12:19,787][WARN ][o.e.b.BootstrapChecks    ] [bitbucket_bundled]max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

Business impact

Insufficient amount of the resources allocated to elasticsearch with those parameters can lead to Code Search and indexing performance issues.

Solution

Introduce the startup check for Elasticsearch related system parameters with notification during the startup.