Nginx cache - could not allocate node in cache keys zone

I have four servers in a pool running nginx with proxy_cache. One of the
nodes started spewing “could not allocate node in cache keys zone”
for every request (which gave 500 status). I did a restart and it
working again.

What conditions cause that error in general?

If it happens again is there anything I can do to try and determine the
root cause?

Same condition on two more of the servers in the same pool. Reload
resolve the issue, but restart does. No limit being hit on disk space,
inodes, open files, or memory.

This is nginx/1.9.0 BTW

At a guess I would say your key zone is full. Try increasing the size of

One other question - is the key zone shared between the worker
Or will each worker allocate its own copy?

I will try that now - but shouldn’t it be evicting a key if it can’t fit
new one?

On Thu, Mar 10, 2016 at 2:38 PM, Richard S.
[email protected]