Do you run intensive read query on slave ?
If yes, query conflict can cause that,
http://www.postgresql.org/docs/9.1/static/hot-standby.html#HOT-STANDBY-CONFLICT
On conflict, xlog stream will be saved on xlog dir on slave instead of
replaying it. This happen until slave has opportunity to write all
Today,our monitor report a pg slave instance'disk space usage reach 96%，I
login in to the machine，and find the pg_xlog dir take up more than
2TB，which is abnormal.
the number of WAL file in the pg_xlog dir is more than 130k,while we set
the wal keep number to 8192.
I think there is something stop t
