seafile使用api上传文件。并发超过1就会500

使用api接口上传文件的时候 并发为1的时候正常。并发超过1,就会报500错误。
nginx 日志如下:
192.168.0.222 - - [23/Oct/2017:21:13:00 +0800] “POST /seafhttp/upload-api/34a32450-1327-4207-b096-9a406df8596e HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:00 +0800] “POST /seafhttp/upload-api/b2fdeaca-f75c-4fac-83d9-603e581258cd HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:01 +0800] “POST /seafhttp/upload-api/01025dba-3886-44e4-9013-db25dc140690 HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:02 +0800] “POST /seafhttp/upload-api/b2fdeaca-f75c-4fac-83d9-603e581258cd HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:03 +0800] “POST /seafhttp/upload-api/01025dba-3886-44e4-9013-db25dc140690 HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:03 +0800] “POST /seafhttp/upload-api/85475686-d3fb-4d9b-bd24-2d4c6faf058c HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:03 +0800] “POST /seafhttp/upload-api/71260ec9-d2c2-4887-884e-4c2881e554e2 HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:03 +0800] “POST /seafhttp/upload-api/34a32450-1327-4207-b096-9a406df8596e HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:04 +0800] “POST /seafhttp/upload-api/b2fdeaca-f75c-4fac-83d9-603e581258cd HTTP/1.1” 500 28 “-” “python-requests/2.18.4”
192.168.0.222 - - [23/Oct/2017:21:13:06 +0800] “POST /seafhttp/upload-api/34a32450-1327-4207-b096-9a406df8596e HTTP/1.1” 500 28 “-” “python-requests/2.18.4”

seafile.log 日志如下:
[10/24/2017 12:04:04 PM] repo-op.c(1078): [post multi-file] Failed to post files to in repo f9e32ac6-a09f-4965-929f-91fe4bbe378c.
[10/24/2017 12:04:05 PM] repo-op.c(1078): [post multi-file] Failed to post files to in repo 6cf6b3f5-adee-4c7c-9db7-413c025ce626.
[10/24/2017 12:04:08 PM] repo-op.c(1078): [post multi-file] Failed to post files to in repo 6cf6b3f5-adee-4c7c-9db7-413c025ce626.
[10/24/2017 12:04:09 PM] repo-op.c(1078): [post multi-file] Failed to post files to in repo f9e32ac6-a09f-4965-929f-91fe4bbe378c.