SERVER-42358 added a test hook to run background validation concurrently with existing tests. The testing runs with the default (wiredTigerGlobalOptions.checkpointDelaySecs) checkpoint frequency of 60 seconds, and the test hook runs over and over again with no pause between runs.

We should consider whether it would be beneficial to run the hook less frequently – say add a sleep to the test hook of some duration – and/or change the checkpoint frequency to less than the 60 second default.

Exploration will probably include fiddling with the settings and seeing if anything bad happens, like bugs.

We committed SERVER-42358 with no pause between runs to let it burn in, and the 60 second default turned up bugs during development where things were and were not checkpoint'ed as expected when tests ran. Not that the test has run for a while, we should reconsider the balance between test coverage and resource utilization – e.g. running the hook without pause can make the test suites slower / take longer.