Hi CouchDB users, I'm trying to replicate a big database: 35 millions documents. Average doc size is 500 bytes.
When replication starts, from server A to server B (from server B in pull mode), we got replicate at 1100 documents per second. Then, after some thousands of documents replicated, replication slowly decelerates until 100 doc/sec. If I restart the couchdb daemon on server B, replication restarts at 1100 doc/sec. And then slow down again. At 100 doc/sec I need multiple weeks to replicate the full database.. :-( Obviously, the two servers are far from their performances limits: one half CPU used (on 16), 10GB of RAM used (on 64GB), and very small I/O (on 24 disks + 2 ssd for cache). You can see here: http://jym.eileo.net/couchdb_req.png , A small graph showing the http requests on server A (almost all GET requests come from server B). The restart of server B is clearly visible at 10:30. I already try to change worker_batch_size, worker_processes and http_connections but this doesn't change anything. Do you know if this is a know bug or how can I improve the situation ? Thank you very much. best, jym
