[initandlisten] connection refused because too many open connections: 819 of 819

早上收到mongodb报警，无法连接。遂爬上服务器查看相关日志信息： 1.现象： 连接数达到819后无法再增加，mongodb无法正常提供服务。 2. 分析

# ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 257321
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65536
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 257321
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

显然不是系统限制的，mongodb最大连接数是20000，查看history信息，发现前次启动没有添加numactl --interleave=all参数。故而重新启动：

# numactl --interleave=all mongod --config /data/mongodb/mongodb.conf
顺道把下面参数也加上了
# echo 0 > /proc/sys/vm/zone_reclaim_mode
# echo 2 > /proc/sys/vm/overcommit_memory

mongodb的NUMA问题参加： http://www.ttlsa.com/html/1211.html 如需转载请注明出处：  connection refused because too many open connections: 819 of 819