Hi Willem,
Compaction would certainly reduce your storage space. You have such a small
number of documents in these databases that it would be a fast operation. Did
you try it and run into issues?
Changing cluster.q shouldn’t affect the overall storage consumption.
Adam
> On May 2, 2019, at 12:15 PM, Willem Bison <wil...@nappkin.nl> wrote:
>
> Hi,
>
> Our CouchDb 2.3.1 standalone server (AWS Ubuntu 18.04) is using a lot of
> disk space, so much so that it regularly causes a disk full and a crash.
>
> The server contains approximately 100 databases each with a reported
> (Fauxton) size of less than 2.5Mb and less than 250 docs. Yesterday the
> 'shards' folders combined exceeded a total 14G causing the server to crash.
>
> The server is configured with
> cluster.n = 1 and
> cluster.q = 8
> because that was suggested during setup.
>
> When I write this the 'shards' folders look like this:
> /var/lib/couchdb/shards# du -hs *
> 869M 00000000-1fffffff
> 1.4G 20000000-3fffffff
> 207M 40000000-5fffffff
> 620M 60000000-7fffffff
> 446M 80000000-9fffffff
> 458M a0000000-bfffffff
> 400M c0000000-dfffffff
> 549M e0000000-ffffffff
>
> One of the largest files is this:
> curl localhost:5984/xxxxxxx_1590
> {
> "db_name": "xxxxxxx_1590",
> "purge_seq":
> "0-g1AAAAFTeJzLYWBg4MhgTmEQTM4vTc5ISXIwNDLXMwBCwxygFFNSApBMqv___39WIgMedXksQJKhAUgBlc4nRu0DiFoC5iYpgOy3J9L-BRAz9-NXm8iQJE_YYgeQxfFEWnwAYvF9oNosADncXo4",
> "update_seq":
> "3132-g1AAAAFWeJzLYWBg4MhgTmEQTM4vTc5ISXIwNDLXMwBCwxygFFMiQ5L8____sxI18ChKUgCSSfYgdUkMDNw1-JQ6gJTGg42UxacuAaSuHqxOAo-6PBYgydAApIBK52clchNUuwCidn9Wog5BtQcgau9nJQoTVPsAohboXsksAJuwX9Y",
> "sizes": {
> "file": 595928643,
> "external": 462778,
> "active": 1393380
> },
> "other": {
> "data_size": 462778
> },
> "doc_del_count": 0,
> "doc_count": 74,
> "disk_size": 595928643,
> "disk_format_version": 7,
> "data_size": 1393380,
> "compact_running": false,
> "cluster": {
> "q": 8,
> "n": 1,
> "w": 1,
> "r": 1
> },
> "instance_start_time": "0"
> }
>
> curl localhost:5984/xxxxxxx_1590/_local_docs
> {"total_rows":null,"offset":null,"rows":[
> {"id":"_local/189d9109518d1a2167b06ca9639af5f2ba16f0a5","key":"_local/189d9109518d1a2167b06ca9639af5f2ba16f0a5","value":{"rev":"0-3022"}},
> {"id":"_local/7b3e0d929201afcea44b237b5b3e86b35ff924c6","key":"_local/7b3e0d929201afcea44b237b5b3e86b35ff924c6","value":{"rev":"0-18"}},
> {"id":"_local/7da4a2aaebc84d01ba0e2906ac0fcb82d96bfe05","key":"_local/7da4a2aaebc84d01ba0e2906ac0fcb82d96bfe05","value":{"rev":"0-3749"}},
> {"id":"_local/9619b06f20d26b076e4060d050dc8e3bde878920","key":"_local/9619b06f20d26b076e4060d050dc8e3bde878920","value":{"rev":"0-172"}}
> ]}
>
> Each database push/pull replicates with a small number of clients (< 10).
> Most of the documents contain orders that are shortlived. We throw away all
> db's 3 times a week as a brute force purge.
> Compacting has been disabled because it takes too much cpu and was
> considered useless in our case (small db's, purging).
>
> I read this:
> https://github.com/apache/couchdb/issues/1621
> but I'm not sure how it helps me.
>
> These are my questions:
> How is it possible that such a small db occupies so much space?
> What can I do to reduce this?
> Would changing 'cluster.q' have any effect or would the same amount of
> bytes be used in less folders? (am I correct in assuming that cluster.q > 1
> is pointless in standalone configuration?)
>
> Thanks!
> Willem
