Temporary files, binlog_cache_size, and row-based binary logging
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Replication is asynchronous by default - slaves need not to connected permanently to receive updates from the master. This means that updates can occur over long-distance connections and even over temporary or intermittent connections such mysql 55 binlog_cache_size a dial-up service. Depending on the configuration, you can replicate all databases, selected databases, or even selected tables within a database.
Scale-out solutions - spreading the load among multiple slaves to improve performance. In this environment, all writes and updates must take place on the master server. Reads, however, may take place on one or more slaves. This model can improve the performance of writes since the mysql 55 binlog_cache_size is dedicated to updateswhile dramatically increasing read speed across an increasing number of slaves. Data security - because data is replicated to the slave, and the slave can pause the replication process, it is possible to run backup services on the slave without corrupting mysql 55 binlog_cache_size corresponding master data.
Analytics - live data can be created on the master, while the analysis of the information can take place on the slave without affecting the performance of the master. Long-distance data distribution - if a branch office would like to work with a copy of your main data, you can use replication to create a local copy of the data for their use without requiring permanent access to the master.
Replication in MySQL mysql 55 binlog_cache_size support for one-way, asynchronous replication, in which one server acts as the master, while one or more other servers act as slaves. With semisynchronous mysql 55 binlog_cache_size, a commit performed on the master side blocks before returning to the session that performed the transaction until at least one slave acknowledges that it has received and logged the events for the transaction.
There are a number of solutions available for setting up replication between two servers, but the best method to mysql 55 binlog_cache_size depends on the presence of data and the engine types you are using.
Replication is controlled through a number of different options and variables. These control the core operation of the replication, timeouts, and the databases and filters that can be applied on databases and tables.
You can use replication to solve a number of different problems, including problems with performance, supporting the backup of different databases, and as part of a larger solution to alleviate system failures. Replication between mysql 55 binlog_cache_size in Mysql 55 binlog_cache_size is based on the binary logging mechanism. The information mysql 55 binlog_cache_size the binary log mysql 55 binlog_cache_size stored in different logging formats according to the database changes being recorded.
Slaves are configured to read the binary log from the master and to execute the events in the binary log on the slave's local database. Once binary logging has been enabled, all statements are recorded in mysql 55 binlog_cache_size binary log. Each slave receives a copy of the entire contents of the binary log.
It is the responsibility of the slave to decide which statements in the binary log should be executed; you cannot configure the master to log only certain events.
If you do not specify otherwise, all events in the master binary log are executed on the slave. If required, you can configure the slave to process only events that apply to particular databases or tables. Each slave keeps a record of the binary log coordinates: The file name and position within the file that it has read and processed from the master.
This means that multiple slaves can be connected to the master and executing different parts of the same binary mysql 55 binlog_cache_size. Because the slaves control this process, individual slaves can be connected and disconnected from the server without affecting the master's operation.
Both the master and each slave must be mysql 55 binlog_cache_size with a unique ID using the server-id option. In addition, each slave must be configured with information about the master host name, log file name, and position within that file.
The details are stored within the slave's master. This section describes the setup and configuration required for a replication environment, including step-by-step instructions for creating a new replication mysql 55 binlog_cache_size.
The major components of this section are:. Events in the binary log are recorded using a number of formats. Once started, the replication process should require little administration or monitoring. This section describes how to set up complete replication of a MySQL server.
There are a number of different methods for setting up replication, and the exact method to use depends on how you are setting up replication, and whether you already have data within your master database.
On the master, you must enable binary logging and configure a unique server ID. This might require a server restart. Mysql 55 binlog_cache_size each slave that you want to connect to the mysql 55 binlog_cache_size, you must configure a unique server ID. You may want to create a separate user that will be used by your slaves to authenticate with the master to read the binary log for replication. The step is optional. Before creating a data snapshot or starting the replication process, you should record the position of the binary log on the master.
You will need this information when configuring the slave so that the slave knows where within the binary log to mysql 55 binlog_cache_size executing events. If mysql 55 binlog_cache_size already have data on your master and you want to use it to synchronize your slave, you will need to create a data snapshot. You will need to configure the slave with settings for connecting to the master, such as the host name, login credentials, and binary log file name and position.
Once you have configured the basic options, you will need to follow the instructions for your replication setup. Mysql 55 binlog_cache_size number of alternatives are provided:. If you are establishing a new MySQL master and one or more slaves, you need only set up the configuration, as you have no data to exchange. If you are mysql 55 binlog_cache_size slaves to an existing replication environment, you can set up the slaves without affecting the master.
If you do not have this privilege, it might not be possible to enable replication. On a replication master, you must enable binary logging and establish mysql 55 binlog_cache_size unique server ID. If this has not already been done, this part of master setup requires a server restart. Binary logging must be enabled on the master because the binary log is the basis for sending data changes from the master to its slaves.
If binary logging is not enabled, replication will not be possible. Each server within a replication group must be configured with a unique server ID. This ID is used to identify individual servers within the group, and must be a positive integer between 1 and 2 32 —1.
How you organize and select the numbers is entirely up to you. Add the following options to the configuration file within mysql 55 binlog_cache_size [mysqld] section. If these options already exist, but are commented out, uncomment the options and alter them according to your needs. For example, to enable binary logging using a log file name prefix of mysql-binand configure a server ID of 1, use these lines:.
If you omit server-id or set it explicitly to its mysql 55 binlog_cache_size value of 0a master refuses connections from all slaves. Ensure that the skip-networking option is not enabled on your replication master.
Mysql 55 binlog_cache_size networking has been disabled, your slave will not able to communicate with the master and replication will fail. On a replication slave, you must establish a unique server ID. If this has not mysql 55 binlog_cache_size been done, this part of slave setup requires a server restart. If the slave server ID is not already set, or the current value conflicts with the value that you have chosen for the master server, you should shut down your slave server and edit the configuration to specify a unique server ID.
If you are setting up multiple slaves, each one must have a unique server-id value mysql 55 binlog_cache_size differs from that of the master and from each of the other slaves.
Think of server-id values as something similar to IP addresses: These IDs uniquely identify each server instance in the community of replication partners. If you omit server-id or set it explicitly to its default value of 0a slave refuses to connect to a master. You do not have to enable binary logging on the slave for replication to be enabled. However, if you enable binary logging on the slave, you can use the binary log for data backups and crash recovery on the slave, and also use the slave as part of a more complex replication topology for example, where the slave acts as a master to other slaves.
Mysql 55 binlog_cache_size slave must connect to the master using a MySQL user name mysql 55 binlog_cache_size password, so there must be a user account on the master that the slave can use to connect. You may wish to create a different account for each slave, or connect to the master using the same account for each slave. You need not create an account specifically for replication.
Mysql 55 binlog_cache_size, you should be aware that the user name and password will be stored in plain text within the master. Therefore, you may mysql 55 binlog_cache_size to create a separate account that has privileges only for the replication process, to minimize the possibility of compromise to other accounts.
For example, to set up a new user, replthat can connect for replication from any host within the mydomain. To configure replication on the slave you must determine the master's current coordinates within its binary log.
You will need this information so that when the mysql 55 binlog_cache_size starts the replication process, it is able to start processing events from the binary log at the correct point. If you have existing data on your master that you want to synchronize on your slaves before starting the replication process, you must stop processing statements on the master, and then obtain its current binary log coordinates and dump its data, before permitting the master to continue executing statements.
If you do not stop the execution of statements, the data dump and the master status information that you use will not match and you will end mysql 55 binlog_cache_size with mysql 55 binlog_cache_size or corrupted databases on the slaves. If you exit the client, the lock is released. The File column shows the name mysql 55 binlog_cache_size the log file mysql 55 binlog_cache_size Position shows the position within mysql 55 binlog_cache_size file.
In this example, the binary log file is mysql-bin. You need them later when you are setting up the slave. They represent the replication coordinates at which the slave should begin processing new updates from the master. In that case, the values that you need to use later when specifying the slave's log file and position are the empty string '' and 4.
You now have the information you need to enable the slave to start mysql 55 binlog_cache_size from the binary log in the correct mysql 55 binlog_cache_size to start replication. The idea here is to prevent any further changes so that the data copied to the slaves is in synchrony with the master.
If you are setting up a brand new master and slave replication group, you can exit the first session to release the read lock. One way to create a snapshot of the data in an existing master database is to use the mysqldump tool. Once the data dump has been completed, you then import this data into the slave before starting the replication process.
To obtain a snapshot of the data using mysqldump:. If you have not already locked the tables on the server to prevent statements mysql 55 binlog_cache_size update data from executing:. The point in time of your snapshot and the binary log position must match. In another session, use mysqldump to create a dump either of all the databases you want to replicate, or of selected individual databases. When choosing databases to include in the dump, remember to filter out databases on each slave that you do not want to include in the replication process.