• Docker builds: Increase stack size to 2MB to prevent rare crashes
  • Alpine has a very small stack size by default (80kb) which is less than
    the default that Postgres expects (100kb). Since there is no good reason
    to reduce it to such a small amount, increase to usually common Linux
    default of 2MB stack size.
  • This would have surfaced as a hard crash of the Docker container with
    error code 137 or 139, easily confused with out of memory errors, but
    clearly distinct from it.
• Reduce timeout for accessing EC2 instance metadata service
  • Previously we were re-using our shared HTTP client, which has a rather
    high timeout (120 seconds) that causes the HTTP client to wait around
    for a long time. This is generally intentional (since it includes the
    time spent downloading a request body), but is a bad idea when running
    into EC2's IDMSv2 service that has a network-hop based limit. If that
    hop limit is exceeded, the requests just go to nowhere, causing the
    client to wait for a multiple of 120 seconds (~10 minutes were observed).
• Don't use pganalyze query marker for "--test-explain" command
  • The marker means the resulting query gets hidden from the EXPLAIN plan
    list, which is what we don't want for this test query - it's intentional
    that we can see the EXPLAIN plan we're generating for the test.