mongodb查看锁信息

serverStatus 的输出中可以看到锁的信息
Dividing locks.timeAcquiringMicros by locks.acquireWaitCount can give an approximate average wait time for a particular lock mode.

locks.deadlockCount provide the number of times the lock acquisitions encountered deadlocks.

If globalLock.currentQueue.total is consistently high, then there is a chance that a large number of requests are waiting for a lock. This indicates a possible concurrency issue that may be affecting performance.

If globalLock.totalTime is high relative to uptime, the database has existed in a lock state for a significant amount of time.
连接的信息
globalLock.activeClients contains a counter of the total number of clients with active operations in progress or queued.
connections is a container for the following two fields:
connections.current the total number of current clients that connect to the database instance.
connections.available the total number of unused connections available for new clients.
对读多及写多的不同场景的应对情况
For read-heavy applications, increase the size of your replica set and distribute read operations to secondary members.

For write-heavy applications, deploy sharding and add one or more shards to a sharded cluster to distribute load among mongod instances.

操作系统资源设置
ulimit -a
-t: cpu time (seconds) unlimited
-f: file size (blocks) unlimited
-d: data seg size (kbytes) unlimited
-s: stack size (kbytes) 8192
-c: core file size (blocks) 0
-m: resident set size (kbytes) unlimited
-u: processes 192276
-n: file descriptors 21000
-l: locked-in-memory size (kb) 40000
-v: address space (kb) unlimited
-x: file locks unlimited
-i: pending signals 192276
-q: bytes in POSIX msg queues 819200
-e: max nice 30
-r: max rt priority 65
-N 15: unlimited
推荐设置
-f (file size): unlimited
-t (cpu time): unlimited
-v (virtual memory): unlimited [1]
-n (open files): 64000
-m (memory size): unlimited [1] [2]
-u (processes/threads): 64000