Thread safety

[Yarek Kowalik]

I'm about to start using montezuma, and would like to get some
guidance on the thread safety. Here are my questions:

- Can montezuma handle multiple readers safely?

- How about updates to the store: does that require any locking?

- Is it OK to have multiple writers or is preferable to have a single
writer?

- Can readers and writers co-exist, or does the writer require an
exclusive access to the store?

Many thanks in advance for all the answers!

Yarek

[John Wiseman]

Montezuma currently has no support for multithreaded or multiprocess
access to the index. I think multiple readers should be OK, though.

John

[Yarek Kowalik]

What might happen if a writer is writing while a reader is reading
from the store? If it's only that I would be getting incomplete
results, then I can live with that if the next read would be
complete. Otherwise, I can write appropriate locking around reading/
writing, at some performance loss. Is locking necessary you think?

Please advise.

Thanks,

Yarek

[Yarek Kowalik]

>  I think multiple readers should be OK, though.

What about then the optimize-index is being run? I'm guessing reading
is not safe then.

Yarek

[Leslie P. Polzer]

>>  I think multiple readers should be OK, though.
>
> What about then the optimize-index is being run? I'm guessing reading
> is not safe then.

My rough guess is that you should lock both reads and writes;
a read may flush pending writes if I got that correctly from the
code.