BE节点经常挂，看日志报错为：
W1208 11:14:53.086174 71836 system_allocator.cc:52] Disable aggressive memory decommit
W1208 11:14:53.090113 72130 utils.cpp:90] Fail to get master client from cache. host= port=0 code=THRIFT_RPC_ERROR
W1208 11:14:53.090555 72130 task_worker_pool.cpp:1060] Fail to report task to :0, err=-1
这是be挂了，可以看下be.out和dmesg -T(是否有oom)，另外建议/proc/sys/vm/overcommit_memory配置为1，配置方式echo 1 > /proc/sys/vm/overcommit_memory