I already did. Is there something specific I should look after in that debug log?

Here a little extract (note: I replaced the request with <removed>):

...
2016/06/19 19:53:11 [debug] 8724#0: *19047 event timer: 63, old: 1466358851127, new: 1466358851267
2016/06/19 19:53:11 [debug] 8724#0: *19047 http upstream exit: 0000000000000000
2016/06/19 19:53:11 [debug] 8724#0: *19047 finalize http upstream request: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 finalize http proxy request
2016/06/19 19:53:11 [debug] 8724#0: *19047 free rr peer 1 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 close http upstream connection: 63
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 0000000031A9EE00, unused: 48
2016/06/19 19:53:11 [debug] 8724#0: *19047 event timer del: 63: 1466358851127
2016/06/19 19:53:11 [debug] 8724#0: *19047 reusable connection: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 http upstream temp fd: -1
2016/06/19 19:53:11 [debug] 8724#0: *19047 http finalize request: 0, "<removed>" a:1, c:1
2016/06/19 19:53:11 [debug] 8724#0: *19047 http terminate request count:1
2016/06/19 19:53:11 [debug] 8724#0: *19047 http terminate cleanup count:1 blk:0
2016/06/19 19:53:11 [debug] 8724#0: *19047 http posted request: "<removed>"
2016/06/19 19:53:11 [debug] 8724#0: *19047 http terminate handler count:1
2016/06/19 19:53:11 [debug] 8724#0: *19047 http request count:1 blk:0
2016/06/19 19:53:11 [debug] 8724#0: *19047 http2 close stream 3, queued 0, processing 1
2016/06/19 19:53:11 [debug] 8724#0: *19047 http close request
2016/06/19 19:53:11 [debug] 8724#0: *19047 http log handler
2016/06/19 19:53:11 [debug] 8724#0: *19047 run cleanup: 000000002DDEE350
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 00000000355360C0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 00000000202F2600, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000001E88A800, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000002DDED500, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 00000000207AF4B0, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000002027BE40, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000002FCE5840, unused: 1348
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000003DABCC40
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000001D295C40
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 0000000024A93CD0, unused: 0
2016/06/19 19:53:11 [debug] 8724#0: *19047 free: 000000001D2E8D10, unused: 828
2016/06/19 19:53:11 [debug] 8724#0: *19047 post event 000000000582ABD0
2016/06/19 19:53:11 [debug] 8724#0: *19047 delete posted event 000000000582ABD0
2016/06/19 19:53:11 [debug] 8724#0: *19047 http2 handle connection handler
2016/06/19 19:54:12 [alert] 8724#0: *19047 open socket #236 left in connection 181
...