Error during couchdb filtered replication with params

Question

I'm trying to run a filtered replication on two different machines, I realized that this only happens when doing a pull replication, if I do a push replication it works fine.

curl -X POST http://localhost:5984/_replicate -d '{\"source\":\"http://MARTIN-NEWPC:5984/pdlib\",\"target\":\"pdlib\",\"filter\":\"replication/SINGLE_COLLECTION\",\"query_params\":{\"key\":\"bb579347-9bfb-4dda-84eb-622b43108872\"}}' -H "Content-Type: application/json"

The cryptic response I get from that request is:

{"error":"json_encode", "reason":"{bad_term, <0.20050.0>}"}

And the debug output in the target couchdb log file is:

[Mon, 17 Oct 2011 01:20:48 GMT] [debug] [<0.476.0>] 'GET' /pdlib/_changes?key=bb579347-9bfb-4dda-84eb-622b43108872&filter=replication/SINGLE_COLLECTION&style=all_docs&heartbeat=10000&since=0&feed=normal {1,
                                                                                                                                                        1}
Headers: [{'Accept',"application/json"},
          {'Content-Length',"0"},
          {'Host',"MARTIN-NEWPC:5984"},
          {'User-Agent',"CouchDB/1.0.2"}]

[Mon, 17 Oct 2011 01:20:48 GMT] [debug] [<0.476.0>] OAuth Params: [{"key","bb579347-9bfb-4dda-84eb-622b43108872"},
               {"filter","replication/SINGLE_COLLECTION"},
               {"style","all_docs"},
               {"heartbeat","10000"},
               {"since","0"},
               {"feed","normal"}]

[Mon, 17 Oct 2011 01:20:48 GMT] [info] [<0.476.0>] 192.168.2.3 - - 'GET' /pdlib/_changes?key=bb579347-9bfb-4dda-84eb-622b43108872&filter=replication/SINGLE_COLLECTION&style=all_docs&heartbeat=10000&since=0&feed=normal 200

[Mon, 17 Oct 2011 01:20:48 GMT] [error] [<0.476.0>] attempted upload of invalid JSON (set log_level to debug to log it)

[Mon, 17 Oct 2011 01:20:48 GMT] [debug] [<0.476.0>] Invalid JSON: <<"bb579347-9bfb-4dda-84eb-622b43108872">>

[Mon, 17 Oct 2011 01:20:48 GMT] [info] [<0.476.0>] 192.168.2.3 - - 'GET' /pdlib/_changes?key=bb579347-9bfb-4dda-84eb-622b43108872&filter=replication/SINGLE_COLLECTION&style=all_docs&heartbeat=10000&since=0&feed=normal 400

[Mon, 17 Oct 2011 01:20:48 GMT] [debug] [<0.476.0>] httpd 400 error response:
 {"error":"bad_request","reason":"invalid UTF-8 JSON"}

In case you need to know, this is the filter function:

function (doc, req) {
    if (doc.type == 'collection' || doc.type == 'document') {
        for (var i in doc.path) {
            if (doc.path[i] == req.query.key) {
                return true;
            }
        }
    }
    return false;
}

Any ideas about the possible cause?

natevw natevw · Accepted Answer · 2011-11-16T17:06:35

It's common to get a 400 "invalid UTF-8 JSON" error when CouchDB tries to interpret one of your query values as JSON when it's a raw (unquoted) string instead. In this case the replication config results in this HTTP request:

GET /pdlib/_changes?key=bb579347-9bfb-4dda-84eb-622b43108872&filter=replication/SINGLE_COLLECTION&style=all_docs&heartbeat=10000&since=0&feed=normal 400

The _changes feed itself doesn't use a key parameter, but normal CouchDB _view queries do — and there expect it to be a JSON value! — so you might try renaming that query_param to something different.

(Somewhat unfortunately, user-defined filter (and list, etc.) functions share the query parameter namespace with CouchDB itself...you may want to prefix your custom parameters with something that's unlikely to conflict with current or future builtin options, e.g. myapp_key.)

Error during couchdb filtered replication with params

2 Answers