postgresql streaming replication

Postgresql fatal error: Reserved connection locations are reserved for Super Users who execute non-replication requests, and postgresql Super Users Recently, database monitoring of the monitoring system is always delayed. An error is reported when you view the log: 10:20:19, 534 ERROR Traceback (most recent call last): File "oracle_mon.py", line 306, in Check t

will wait for a file/tmp/start_me_up.txt to make the condition set. The content of this file is completely irrelevant; PostgreSQL simply checks to see if the file exists and, if so, stops the recovery and converts itself to master.Creating an empty file is fairly straightforward work:imac:slavehs$ Touch/tmp/start_me_up.txtThe database system will respond to the new file Start_me_up.txtFatal:terminating Walreceiver proced Fire up:Log:trigger file foun

wal_keep_segments heavily. The idea of this postgresql.conf setup is to keep master in more Xlog files than is theoretically needed. If you set the variable to 1000, it means that master will keep the xlog above 16GB. In other words, your slave can disappear 16GB compared to normal (convert to master). This greatly increases the slave's advantage of joining a cluster without having to fully synchronize itself from the beginning. For a 500MB database this is not worth mentioning, but if your set

functionality in PostgreSQL, called Primary database or master database, is called Hot from a library server that receives the master library synchronizing data while providing read services. Standby server.PostgreSQL maintains a Wal log file in the Pg_xlog subdirectory of the data directory that records each change to the database file, which provides a way for a database to be hot-backed, namely: Back up the database using the file system and als

example only). We decided to use MD5 as the authentication method. This means that the pg_basebackup must provide a password to the server. If you use trust as a certification method in a low-security environment, it may also be a choice.[What happens if you really have a database called replication in your system?] Basically, setting up a database for replication only configures your

pg_stop_backup ();Notice:wal archiving is not enabled; You must ensure it all required WAL segments is copied through other means to complete the backupPg_stop_backup----------------0/2000238(1 row)So far, everything is the same as regular stream replication-the only difference is that not all directories of the underlying directory are actually synchronized to slave.In the next steps, create a simple recovery.conf file:slave]$ Cat recovery.confPrima

target library initialization parametersAlter system set AQ_TM_PROCESSES=4 Scope=spfile;Alter system set JOB_QUEUE_PROCESSES=5 Scope=spfile;Alter system set GLOBAL_NAMES=TRUE Scope=spfile;Alter system set STREAMS_POOL_SIZE=51M Scope=spfile;Note Streams_pool_size is best >200m in the production environmentb Source Library and Target library Tnsnames.ora configurationSee 4.1C Source Library and Target Library replication Administrator's creationSee 4.1

Label:One, Standby synchronous replication node downpostgres=#select*frompg_stat_replication; pid|usesysid|usename|application_name| client_addr|client_hostname|client_port| backend_start|backend_xmin |NBSP;NBSP;NBSP;STATENBSP;NBSP;NBSP;|NBSP;SENT_LOCATIONNBSP;|NBSP;WRITE_LOCATIONNBSP;|NBSP;FL Ush_ location|replay_location|sync_priority|sync_state-------+----------+ ----------+------------------+-------------+-----------------+-------------+----------

these fields in more detail: PID: This represents the process ID of the wal_receiver process that is responsible for streaming connections. If you check your process table on your operating system, you should find a PostgreSQL process with that number. Usesysid: Each internal user has a unique number. The system works much like Unix. Usesysid is the unique identifier of the (

required:shared_preload_libraries = ' BDR 'Wal_level = ' logical 'Track_commit_timestamp = Onmax_connections = 100Max_wal_senders = 10Max_replication_slots = 10Max_worker_processes = 10The first thing to do is to load the BDR module into PostgreSQL. It contains important infrastructure for replication. Next, you must enable logical decoding. It will be the backbone of the entire infrastructure.To get the B

/pgsql/data/recovery.conf 复制完成后修改如下内容： ?standby_mode = ‘on‘ primary_conninfo =‘host=10.0.2.69??port=5432 user=repuser password=repuser keepalives_idle=60‘ Start the Slave library正常启动备库，有异常可以看log /usr/local/pgsql/bin/pg_ctl start -D /usr/local/pgsql/data >>logfile 2>1 View the main library and boot status from the libraryMaster:Slave: At this point, the PostgreSQL streaming

few milliseconds) or very long (minutes, hours, days). One important fact is that the data may be lost. A small lag is less likely to be a data loss, but any lag greater than 0 can easily lead to data loss.If you want to make sure that data is never lost, you must switch to synchronous replication. As you have seen in this section, a synchronous transaction is synchronous because it is valid if the thing is committed to two servers.Consider performan

the master if there are incorrect data replication 2.4boot the main library to view the configuration results Postgres=#select * from Pg_stat_replication;-[RECORD1]----+------------------------------PID|1793Usesysid|24576Usename|replica Application_name|Walreceiver client_addr|192.168.1.203Client_hostname|Client_port|32250Backend_start| .- the- on A: at:16.924496+ ,Backend_xmin|1676 State|Streaming Sent_

Xlog file. The server provides a process called pg_switch_xlog () to do this work:test=# SELECT Pg_switch_xlog ();Pg_switch_xlog----------------0/17c0ef8(1 row)You might call this process when some important patching work is done or you want to make sure that a particular database is securely present in your Xlog archive.3.5 SummaryIn this chapter, you've learned about instant recovery, a safe and easy way to recover your PostgreSQL database to any t

Tags: PostgreSQL synchronous stream replication Node Ip Role Master 10.10.100.1 Master Standby1 10.10.100.2 Standby1 Standby2 10.10.100.3 Standby2 The user that is required to create the stream replication on master.CREATE ROLE

Label:Pgpool Overview The Pgpool-ii is a middleware located between the PostgreSQL server and the PostgreSQL database client, which provides the following features: Connection pooling, replication, load balancing, limiting over-limit connections, and parallel queries. Document here. Four types of modes O means "available" and X means "not available(

syncs Resumed:bard $ tail Log.bucardo (27344) KID (bard) Delta count for S1.public. " Character ": 1 (27344) KID (bard) Delta count for S2.public." Character ": 1 (27344) KID (bard) Conflicts for public." Character ": 1 (27344) KID (bard) Conflicts have been resolved (27344) KID (bard) totals:deletes=2 inserts=2 con Flicts=1 Bucardo 5 is a lot more powerful than the demo we have here. In future blog posts, we'll include other features that it can do from

Use Bucardo5 to implement master database replication of PostgreSQL, bucardo5postgresql The next generation of asynchronous primary database replication system Bucardo 5 is released. This version removes the restrictions on two database sources in the old version, allowing more source databases (Primary databases) and more target databases (Backup databases ). Bu

Tags: PostgreSQL asynchronous stream replication standby auto-activation Node Ip Role Citus-master 10.10.100.1 Master Citus-standby 10.10.100.2 Standby The user that is required to create the stream replication on master.CREATE ROLE replica