Couchbase Community Edition as a Cache

Question

It is mentioned here(http://www.couchbase.com/memcached) that couchbase can be used as the caching layer. I am supposed to use the community edition for my caching layer. As found in Internet, there are many large scale organizatios are using for heavy usage, but the size of their caches are around 1kb to 100kb. I want to know,

1. will there be a performance draw backs when large objects(1mb-10mb size) are cached and when it is replicated ?

2. will data be synchronized/replicated among nodes as soon as they are updated

   any one has experience?

Answer 1

To answer your questions:

Will there be a performance draw backs when large objects(1mb-10mb size) are cached and when it is replicated ?

Couchbase has a maximum document size of 20MB for Couchbase type buckets. Depending on your settings each document will need to be written both to disk and across the network to each replica node. Other than the actual disk / network bandwidth required for this you shouldn't see any particular performance issues.

Will data be synchronized/replicated among nodes as soon as they are updated?

As documented in the Couchbase Admin Guide, data is queued to be replicated to replica nodes as soon as it is received by the master.

Couchbase automatically shards each Bucket into a number of vBuckets, and each vBucket is "owned" by just a single master node, so a client will normally only need to communicate with one node for a particular document; therefore replication time isn't relevant for consistency (it's mainly there to provide backup copies in the event of a node failure).

You may also want to look at the high level Architecture and Concepts of Couchbase to see how it all fits together.