Cleanup ops

[destitutus]

Improvement:

1. Allow cleanup ops collection by mongo ttl (options value)
2. Cache collections

Related #5

[josephg]

If we're going to do this, we also need livedb tests so we know how livedb will respond when old operations are requested and they aren't available.

[destitutus]

Some statistics - we have 12kk records

[destitutus]

If we're going to do this, we also need livedb tests so we know how livedb will respond when old operations are requested and they aren't available.

I try implement test if I will have time for it

[josephg]

👍

[destitutus]

so, cleanup ops only in mongo can raise issues with oplogs
we start use separate program for cleanup - https://github.com/destitutus/sharejs-cleaner