CouchDB v1.2.0 - 复制超时错误

Question

目前，我有一个如下所示的复制任务：

{
   "continuous": true,
   "create_target": true,
   "owner": "admin",
   "source": "https://remote/db/",
   "target": "db",
   "user_ctx": {
       "roles": [
           "_admin"
       ]
   }
}

使用 http 时，我在日志中看不到任何错误。使用 https 时，从技术上讲，复制确实有效，但日志中也出现了大量错误。我想修复这些错误。

错误如下：

[Fri, 01 Nov 2013 22:11:49 GMT] [info] [<0.2227.0>] Retrying GET request to https://remote/db/doc?atts_since=%5B%2271-315ddf7e3d31004df5cd00846fd1cf38%22%5D&revs=true&open_revs=%5B%2275-a40b4c7d00c17cddcbef5b093bd10392%22%5D in 0.5 seconds due to error req_timedout

但是，我可以访问curl这些 URL 而不会超时：

$ curl -k 'https://remote/db/doc?atts_since=%5B%2273-7a26ae649429b96ed01757b477af40bd%22%5D&revs=true&open_revs=%5B%2276-c9e25fe15497c1c60f65f8da3a68d57d%22%5D'
<returns a bunch of garbage (expected garbage ;)>

我connection_timeout在 Couchdb 复制上设置了一个非常慷慨的 120 秒：

[Fri, 01 Nov 2013 22:13:00 GMT] [info] [<0.3359.0>] Replication `"36d8a613224f3749a73ae4423b5f9733+continuous+create_target"` is using:
    4 worker processes
    a worker batch size of 500
    20 HTTP connections
    a connection timeout of 120000 milliseconds
    10 retries per request
    socket options are: [{keepalive,true},{nodelay,true}]
    source start sequence 100321

我想不出有什么显著差异，以至于 curl 在几秒钟内收到响应，而 CouchDB 复制器在 120 秒内超时。我遗漏了什么，我还能尝试调整什么？

CouchDB v1.2.0 在 Ubuntu 13.04 上运行 Linux ip-10-40-65-137 3.8.0-32-generic #47-Ubuntu SMP Tue Oct 1 22:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux