DCP vs TAP in sync gateway


#1

Hi ,

What is the difference between using TAP or DCP in sync gateway config. What it will impact ? Will performance be better in one and not in other?


#2

DCP is being used by default now, and TAP is in the process of being deprecated and will be removed completely from upcoming Couchbase Server versions at some point.

DCP has better restartability / checkpointing support, so that there is less reprocessing of events. Also, for users that use Sync Gateway accelerator, DCP is required to supported the sharded DCP feed where SG Accel nodes only receive DCP events for a subset of the vbuckets.

As far as performance, I don’t have any numbers to share, but the upcoming SG 1.5 release will be undergoing performance regression testing and the expectation is that overall performance will improve.


#3

So does it mean I should explicitly mention in the feed type in sync gateway config JSON. Currently I am using SG 1.4 . And the documentation says TAP is default. I have issues in restarting sync(it takes time) which I think if I Use DCP it wont take much. Let me change the config and let you know if it improves things.


#4

The current documentation says TAP is default even Sync Gateway 2.0.


#5

Thanks for pointing that out!

I’ve raised a docs PR here: https://github.com/couchbaselabs/couchbase-mobile-portal/pull/866/files