Christian Schwarz 8654e95fae walredo: fix zombie processes ([postgres] <defunct>) ...

This change wraps the std::process:Child that we spawn for WAL redo
into a type that ensures that we try to SIGKILL + waitpid() on it.

If there is no explicit call to kill_and_wait(), the Drop implementation
will spawns a task that does it in the BACKGROUND_RUNTIME.
That's an ugly hack but I think it's better than doing kill+wait
synchronously from Drop, since I think the general assumption in the
Rust ecosystem is that Drop doesn't block.
Especially since the drop sites can be _any_ place that drops the last
Arc<PostgresRedoManager>, e.g., compaction or GC.

The benefit of having the new type over just adding a Drop impl to
PostgresRedoProcess is that we can construct it earlier than the full
PostgresRedoProcess in PostgresRedoProcess::launch().
That allows us to correctly kill+wait the child if there is an error in
PostgresRedoProcess::launch() after spawning it.

I also took a stab at a regression test. I manually verified
that it fails before the fix to walredo.rs.

fixes https://github.com/neondatabase/neon/issues/2761
closes https://github.com/neondatabase/neon/pull/2776

2022-11-10 12:50:50 +01:00

..

benches

Add micro-benchmark for layer map search function

2022-10-18 15:00:10 +03:00

src

walredo: fix zombie processes ([postgres] <defunct>)

2022-11-10 12:50:50 +01:00

Cargo.toml

Move pq_proto to its own crate

2022-11-03 22:56:04 +03:00