Обсуждение: Streaming Replication and Firewall
I updated the firewall rules on a streaming replication standby server and thought nothing of it. I later happened to notice on the primary that ps aux | grep stream didn't show streaming to that server anymore. On the standby that command still showed the wal receiver patiently waiting for new data. I know I broke it, but would anything have eventually happened, or would the wal receiver keep patiently waiting as the world passed it by? I simply restarted the standby cluster and all is well. Thanks! - Ian
On Fri, Sep 30, 2011 at 1:35 AM, Ian Harding <harding.ian@gmail.com> wrote: > I updated the firewall rules on a streaming replication standby server > and thought nothing of it. I later happened to notice on the primary > that ps aux | grep stream didn't show streaming to that server > anymore. On the standby that command still showed the wal receiver > patiently waiting for new data. > > I know I broke it, but would anything have eventually happened, or > would the wal receiver keep patiently waiting as the world passed it > by? I guess that walreceiver has been stuck because it could not detect the termination of connection for a while. By default, keepalive is enabled on the replication connection from the standby to the master, but how long it takes for walreceiver to notice the termination of connection depends on the kernel parameters related to keepalive. By default settings, it takes about two hours. Setting keepalives parameters in primary_conninfo would help to fix such a problem. http://developer.postgresql.org/pgdocs/postgres/libpq-connect.html Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center
On Thu, Sep 29, 2011 at 5:32 PM, Fujii Masao <masao.fujii@gmail.com> wrote: > On Fri, Sep 30, 2011 at 1:35 AM, Ian Harding <harding.ian@gmail.com> wrote: >> I updated the firewall rules on a streaming replication standby server >> and thought nothing of it. I later happened to notice on the primary >> that ps aux | grep stream didn't show streaming to that server >> anymore. On the standby that command still showed the wal receiver >> patiently waiting for new data. >> >> I know I broke it, but would anything have eventually happened, or >> would the wal receiver keep patiently waiting as the world passed it >> by? > > I guess that walreceiver has been stuck because it could not detect > the termination of connection for a while. By default, keepalive is > enabled on the replication connection from the standby to the master, > but how long it takes for walreceiver to notice the termination of > connection depends on the kernel parameters related to keepalive. > By default settings, it takes about two hours. > > Setting keepalives parameters in primary_conninfo would help to fix > such a problem. > http://developer.postgresql.org/pgdocs/postgres/libpq-connect.html > > Regards, > > -- > Fujii Masao > NIPPON TELEGRAPH AND TELEPHONE CORPORATION > NTT Open Source Software Center > Thank you! That was exactly what I needed.