postgresql database replication

4.7 Conflict ManagementIn PostgreSQL, stream replication data flows in only one direction. Xlog is provided by master to several slave that consume transaction logs and provide you with a better backup of your data. You may wonder how this can lead to a conflict, which can occur.Consider the situation: as you know, there is a small delay in data replication. Ther

replication and have shown how data is replicated synchronously. We also described how to change the durability requirements by modifying the operating parameters of PostgreSQL. PostgreSQL gives the user the choice of how to replicate the transaction, and the level of durability required for a particular transactional replication.In the next chapter, we'll drill

Use pg_basebackup to build a PostgreSQL stream replication Environment This article introduces the high availability of PostgreSQL. Here we will first conduct a stream replication experiment. Environment:OS: [Ha @ node0 ~] $ Uname-Linux node0 2.6.32-358. el6.x86 _ 64 #1 SMP Fri Feb 22 00:31:26 UTC 2013 x86_64 x86_64 x8

script will be executed at each restart point. So what is the beginning of the heavy? Each time PostgreSQL transitions from file-based replay to stream-based replay, you are facing a heavy starting point. In fact, starting a stream copy again is considered to be a boot point.Once the start point arrives, you can have PostgreSQL perform some cleanup (or anything else). It is easy to clean out old xlog or tr

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

Label:Catalogue [-] One, high availability, load balancing, replication of several scenarios comparison: Two, multi-node cluster scheme comparison 9.3 Official Document (Chinese): http://58.58.27.50:8079/doc/html/9.3.1_zh/high-availability.html replication, cluster, and connection pooling: https://wiki.postgresql.org/wiki/Replication,_Clusteri

one of the ways that PostgreSQL master-slave replication is implemented:Standby-based asynchronous stream replication, which is a nice feature provided after the postgresql9.x version (2010.9), similar functionality is available in Oracle after 11g for active dataguard and SQL Server Log shipping provided after version 2012, here again for PG applause, is really

Working with WalbouncerIn the final chapter of this book, you will be guided to a tool that was released in 2014, called Walbouncer. Most of the tips in this book show how to replicate an entire database instance, how to Shard, and so on. In the last chapter, it is about Wabouncer, which is all about filtering the transaction log stream to selectively replicate database objects from one server to a group (n

ObjectiveSimply record one of the implementations of PostgreSQL master-slave-asynchronous stream replication based on standby, This is a nice feature that is provided after the postgresql9.x version (2010.9), similar to the log shipping that is provided after the active Dataguard and SQL Server 2012 versions of Oracle are available after 11g, Here again for PG applause, is really a great open source

one line of code and run it; Pg_basebackup will do all the rest for you.In this example, we will assume that we are going to make a basic backup of a host called postgresql-support.de. You must perform the following steps:• Modify pg_hba.conf to allow replication• Signal Master to consider changes in pg_hba.conf• Call Pg_basebackupModify Pg_hba.confIn order to allow a remote server to log on to a

reasons, it may be necessary to maintain and restore replication again and again. Just consider a major software update. It might do some nasty things about your data structure. You absolutely don't want to have the wrong stuff copied to your system. Therefore, it is convenient to stop copying and restart it once it proves to be normal.Two functions can be used for this work:SELECT Bdr.bdr_apply_pause ()To restart again, you can use the following fun

. The goal is to run a transaction that inserts a row. If a crash occurs shortly after submission, no data is at risk because nothing happens. If you crash after an INSERT statement, but before commit, nothing happens. The user has not issued a commit, so the transaction is well known to run, but not completed. If a crash occurs, the application will notice that things are not successful and (hopefully) react accordingly. However, the situation is completely different, and if the user has issued

directory of With-pgconfigdir parameters;In addition Slony-i a set of Perl script tools, named Altperl scripts, can simplify the configuration of Slony-i, the default compilation will not take the script, need to compile, with--with perltools to compile;After compiling the kick, the Slony-i installation is completed, and the general Slony-i is installed in the directory where the PostgreSQL database reside

. [The performance loss of only one connection is certainly larger than in the case of many connections. Keep in mind that you can work in parallel, network latency does not use more of our I/O or CPU bandwidth, so we can reduce the impact of slow transactions by initiating more concurrent work. ] When using synchronous replication, how can you ensure that performance does not suffer too much? Basically, there are several important recommendations tha

the process of use, you need to consider issues such as bandwidth and local caching. It restricts the number of agent libraries to be 2 of the time. Proxy implements the forwarding function on a custom function. This requires a large number of business logic to be put on the PostgreSQL server side to complete, reducing the flexibility of the application. It also poses a challenge for possible future database