I'm using apache with php on amazon linux. I've updated php from 5.3 to 5.5 and apache from 2.2 to 2.4. Now calling
is behaving in a strange way. It works for a while and then starts working only 50% of the time. Apache error log is filled with 'Call to undefined function hash'.
There's no more code around this, I created a separate file with only that function used and half the time I see the hash and other half is http 500.
What could be causing this? How can a module just disappear? I don't see extension=hash.so in any of the ini files but then again it works at the start. Restarting apache helps but I'd like to figure out what's going on. What might be a sane place to start searching from?