Ceph is an open source distributed storage solution. This presentation shows the implementation of Persistent Write Log Cache(PWL cache) at Ceph client side to handle burst writes to reduce backend pressure. PWL cache is a kind of Write Back Cache, but it leverages log to ensure the I/O order. Compared with the traditional volatile cache, PWL cache persists the data to Persistent memory (PMEM). In order to prevent data loss caused by abnormal conditions, we implement Replication for PWL.