Is there a problem with streaming replication in PostgreSQL?
Asynchronous Replication setups in streaming replication can incur problems such as data loss or slave lag, so version 9.1 introduces synchronous replication.
What does zero _ damaged _ pages do in PostgreSQL?
Setting zero_damaged_pages to on causes the system to instead report a warning, zero out the damaged page in memory, and continue processing. This behavior will destroy data, namely all the rows on the damaged page. However, it does allow you to get past the error and retrieve rows from any undamaged pages that might be present in the table.
How to rebuild an inconsistent PostgreSQL slave?
As ClusterControl users all we have to do is to go to the “Nodes” tab and run “Rebuild Replication Slave” job. Next, we have to pick the node to rebuild slave from and that is all. ClusterControl will use pg_basebackup to set up the replication slave and configure the replication as soon as the data is transferred.
What to look for if your PostgreSQL replication is lagging?
PostgreSQL standby nodes, which are in recovery mode, does not report to you the exact state of what’s happening of your replication. Not unless you view the PG log, you can gather information of what’s going on. There’s no query you can run to determine this.
What kind of replication does PostgreSQL use?
For example, you can use physical streaming asynchronous replication or use logical streaming replication. Both are monitored differently though use the same approach when sending data over replication, which is still streaming replication.
When do you commit a transaction in PostgreSQL?
So in With PostgreSQL, the time for a commit is (at minimum) the round trip between the primary and the standby. Read-only transactions will not be affected by that. As it evolves, PostgreSQL is continuously improving and yet its replication is diverse.
When was warm standby introduced in PostgreSQL?
Warm standby for PostgreSQL was implemented in version 8.2 (back in 2006) and was based on the log shipping method. This means that the WAL records are directly moved from one database server to another to be applied, or simply an analogous approach to PITR, or very much like what you are doing with rsync.
What do you need to know about replication lag?
As defined in our previous blog, a replication lag is the cost of delay for transaction (s) or operation (s) calculated by its time difference of execution between the primary/master against the standby/slave node.
How does a write transaction work in synchronous replication?
In synchronous replication, each commit of a write transaction will wait until confirmation is received that the commit has been written to the write-ahead log on disk of both the primary and standby server.