
973b983 Merge branch 'release-2.0.0' into develop 255dd23 Make spinlock functions take const argument 6e23bab Fix bitmask reallocation 338c189 Rename and clean up slavelag filter 3ea8f28 Fix possible NULL pointer dereference bfe6738 MXS-830: Add module information to logged messages 1fad962 Fix strncat usage d38997a Adjust log throttling policy 0be4e4b Add hashtable_item_strcasecmp 726100e Take hashtable convenience functions into use 5e7744a Fix typo in maxadmin.md c5778c8 Merge branch 'release-2.0.0' into develop b5762af Move from tmpnam to mkstemp d6f2c71 Add convenience functions to hashtable 359058a MXS-825: Add support for --execdir 636347c Enable runtime reconfiguration of log throttling ef9fba9 Improve log throttling documentation aef917a Implement log throttling e3a5349 Remove shardrouter.c 8051e80 Remove custom qc_sqlite allocation functions fd34d60 Initial implementation of the learning firewall a8752a8 Removed "filestem option" from example 1ef2519 Removed "filestem option" from example 0815cc8 Cleanup spinlock.h ab4dc99 Clean up hashtable.h ef2c078 Add prototypes for hashtable copy and free functions fb5cfaf Add 'log_throttling' configuration entry 300d823 Add proper prototypes for hashtable hash and cmp functions 1c649aa qc_mysqlembedded: Include skygw_...h without path. d276160 Add missing RPM scripts e70e644 Fix HTTPAuth installation 1b2b389 Combine utils into the server directory 3ff9913 Add missing utils headers to devel package 407efb2 Fix minor packaging problems 99aa6ad Split MaxScale into core, experimental and devel packages 1290386 Merge branch 'develop' of ssh://github.com/mariadb-corporation/maxscale-new into develop e59f148 Make scripts POSIX sh compatible 7319266 Fixed SHOW SLAVE STATUS in bonlog router f8d760a Update Binlogrouter.md 0a904ed Update Replication-Proxy-Binlog-Router-Tutorial.md 75d4202 Update Replication-Proxy-Binlog-Router-Tutorial.md b8651fc Add missing newline in listmanager.h c7ad047 Add note about user data caches to release notes 70ccc2b Merge branch 'release-2.0.0' into develop 575d1b6 Mistake - dummy session needs list markers set. 8364508 Merge branch 'develop' into binlog_server_semisync 868b902 Update MaxScale limitations 2c8b327 Store listener caches in separate directories 6e183ec Create unique user data caches for each listeners f643685 Don't free orphaned tee filter sessions 4179afa Allow binlogrouter to be used without a listener 7ad79af Add function for freeing a listener 677a0a2 Move authentication data from services to listeners 4f12af7 Merge remote-tracking branch 'origin/MXS-677' into develop 1419b81 Semi-Sync support to binlog server: code review updtate 0ea0f01 Semi-Sync support to binlog server: added missing routine 4aad909 Semi-Sync support to binlog server b824e1e Add authenticator support to httpd.c 705a688 Change tabs to spaces d0c419e Change method of adding list fields to e.g. DCB 25504fc Document the changed routing priority of hints 41666d1 Remove use_ssl_if_enabled global option a3584e9 Make routing hints have highest priority 34a1d24 Updated document with new binlog router option 01eedc5 Updated documentation with SSL usage 8a4c0f6 Update Replication-Proxy-Binlog-Router-Tutorial.md 4e374aa Update Replication-Proxy-Binlog-Router-Tutorial.md f3f3c57 Update Replication-Proxy-Binlog-Router-Tutorial.md 617b79f Binlog Server: error messages typo fix fa8dfae Binlog Server: error messages review 1b8819c Fix freeing of schemarouter session memory 07f49e1 MXS-788: new code review fix 1fd3b09 MXS-788: show services now displays SSL info 6ca2584 MXS-788 code review fix ae6a7d0 MXS-788 code review 43d3474 Master server SSL connection 90b2377 Use correct variable in listmanager pre-allocation 9a5b238 Fix listmanager pre-allocation 9c78625 Fix a memory leak when backend authentication fails e59a966 Fix hang in list_find_free ff30223 Fix freeing of shared data in schemarouter fc8f9d3 Add missing include in luafilter ecf7f53 Add missing NULL value to filter parameter array 636d849 Update memory allocation approach f0d1d38 Add new allocation functions 97d00a0 Fix writing of uninitialized data to logs e72c9b2 Merge branch 'release-2.0.0' into develop cf2b712 Merge branch 'release-2.0.0' into develop 8917c5c Change the logic behind valid list entry checks c10deff Improve documentation about version_string f59f1f7 Merge branch 'develop' of ssh://github.com/mariadb-corporation/maxscale-new into develop c88edb3 Backend authentication failure improvement abd5bee Revert "Backend authentication failure improvement" 5bb3107 Backend authentication failure improvement b7f434a Add new allocation functions 3f022fa Fix stupid mistake 99c4317 Merge remote-tracking branch 'origin/MXS-677' into develop 3c1ded6 Added connection/authentication failure error reporting in SHOW SLAVE STATUS 0a60f7b Tidy up and deal with review points. ba103ff blr_slave.c: Update strncpy usage 467331e blr_master.c: Strncpy usage updates d2b7c0c Merge remote-tracking branch 'origin/develop-nullauth-merge' into develop 5a8c1d0 qc: Measure execution time at the right place. bccdb93 Merge branch 'NullAuthDeny' into develop 2e6511c Add 5.5.5 prefix to all version strings that lack it 314655a Improve DCB and session initialization and list handling e1c43f0 MXS-655: Make MaxScale logging logrotate(8) compatible ce36afd MXS-626: Don't log a header unless maxlog enabled dcd47a7 blr_file.c: Replace uses of strncpy 6b8f576 bls_slave.c: Replace strncpy with memcpy 68a0039 Add list preallocation, tidy up, simplify init. cb37d1b Fix copyright etc headers. 11a400d Tidy; comment; fix bad copies and mistakes. 7e36ec4 Add list manager files. c4794e3 Initial code for list manager. 1b42e25 Merge remote-tracking branch 'origin/MXS-765' into develop d50f617 Fix problems, extend tests, respond to review. dcb4a91 Filter test folder removed 0b60dbe Add a couple of comments. 83cdba0 Fix overwriting problem. ba5d353 Fix overwriting problem. 53671cb Small fixes in response to review. 173d049 blr.c: Review strncpy usage 4ff6ef2 binlog_common.c: Replace strncpy with memcpy f238e03 maxbinlogcheck.s: Replace strncpy 9807f8d harness: Replace unnecessary use of strncpy 8c7fe6a avro: Modify strncpy usage 9b8008e Small improvements. b7f784f Fix mistakes in testqueuemanager.c cc26962 Restore missing poll.c code; add testqueuemanager.c. 2e91806 Format the filter harness 22059e6 Initial implementation connection queueing. c604dc2 readwritesplit.c: Improve COM_INIT_DB handling 454d920 schemarouter.c: Replace strncpy with strcpy 8e85d66 sharding_common.c: Too long a database name handled explicitly 77f4446 Astyle schemarouter 491f7c2 maxinfo.c: Replace strncpy with memcpy 6b98105 maxinfo: Reformat with astyle c1dbf08 Handle oversize user and database names 5fa4a0f Merge branch 'develop' of ssh://github.com/mariadb-corporation/maxscale-new into develop 706963b BLR_DBUSERS_TAIL new var in blr.h d75b9af Tweak comments, remove trailing blanks. ab2400a Optimise statistics gathering by inline & simpler fns. fb59ddc Remove unnecessary strncpy/strncat usage in Binlog Server bdcd551 resultset.c: Change strncpy to memcpy c6b1c5e Reject rather than cut too long a path 6d8f112 Remove unnecessary strncpy/strncat usage 18bf5ed Remove unnecessary strncpy usage dc0e2db Make maxpasswd more userfriendly c9c8695 Fix calculation of padded_len in encryptPassword 2cfd2c6 dbusers.c: Check strncpy usage 7ab9342 Make more thorough checks in secrets_readKeys be7d593 Format cli.c debugcli.c testroute.c webserver.c 1ee5efb config.c: Check usage of strncpy 3043b12 gq_utils.c: Unnecessary use of strncpy removed 77874ac Add help to maxkeys 38392a3 Update secrets_writeKeys documentation 2d1325c Make SSL optional in MaxScale's own communication bda00da Fix avro build failures b2cb31a Add more OOM macros 41ccf17 Fix strdup usage a48f732 Fix realloc calls 20771f6 Add forgotten extern "C" block 8faf35a Add maxscale allocation functions bb47890 Add macros for OOM logging afea388 Fix silly mistakes. 6dafd22 Make deny default for null auth; move code from common to auth.
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MariaDB MaxScale as a Binlog Server
MariaDB MaxScale is a dynamic data routing platform that sits between a database layer and the clients of that database, the binlog router described here is somewhat different to that original concept, moving MariaDB MaxScale down to play a role within the database layer itself.
In a traditional MySQL replication setup a single master server is created and a set of slaves MySQL instances are configured to pull the binlog files from that master to the slaves. There are some problems, however, in this setup; when the number of slaves grows an increasing load is placed on the master, to serve the binlogs to each slave. When the master server fails, some action must be performed on every slave server before a new server can become the master server.
Introducing a proxy layer between the master server and the slave servers can improve the situation, by reducing the load on the master to simply serving the proxy layer rather than all of the slaves. The slaves only need to be aware of the proxy layer and not of the real master server. Removing need for the slaves to have knowledge of the master, greatly simplifies the process of replacing a failed master within a replication environment.
MariaDB/MySQL as a Binlog Server
The most obvious solution to the requirement for a proxy layer within a replication environment is to use a MariaDB or MySQL database instance. The database server is designed to allow this, since a slave server is able to be configured such that it will produce binary logs for updates it has itself received via replication from the master server. This is done with the log_slave_updates configuration option of the server. In this case the server is known as an intermediate master, it is simultaneously a slave to the real master and a master to the other slaves in the configuration.
Using an intermediate master does not, however, solve all the problems and introduces some new ones, due to the way replication is implemented. A slave server reads the binary log data and creates a relay log from that binary log. This log provides a source of SQL statements, which are executed within the slave in order to make the same changes to the databases on the slaves as were made on the master. If the log_slave_updates option has been enabled, new binary log entries are created for the statements executed from the relay log.
The above means that the data in the binary log of the intermediate master is not a direct copy of the data that was received from the binary log of the real master. The resultant changes to the database will be the same, provided no updates have been performed on the intermediate master that did not originate on the real master, but the steps to achieve those changes may be different. In particular, if group commit functionality is used, to allow multiple transactions to commit in parallel, these may well be different on the intermediate master. This can cause a reduction in the parallelism of the commits and a subsequent reduction in the performance of the slave servers.
This re-execution of the SQL statements also adds latency to the intermediate master solution, since the full process of parsing, optimization and execution must occur for every statement that is replicated from the master to the slaves must be performed in the intermediate master. This latency introduces lag in the replication chain, with a greater delay being introduced from the time a transaction is committed on the master until the data is available on the slaves.
Use of an intermediate master does improve the process of failover of the master server, since the slaves are only aware of the intermediate master the process of promoting one of the existing slaves to become the new master only involves that slave and the intermediate master. A slave can become the new master as soon as all the changes from the intermediate master have been processed. The intermediate master then needs to be reset to the correct point in the binary log of the new master and replication can continue.
An added complexity that needs to be dealt with is the failure of the intermediate master itself. If this occurs then the same problem as described earlier exists, all slaves must be updated when a new intermediate master is created. If multiple intermediate masters are used, there is also a restriction that slaves can not be moved from the failed intermediate master to another intermediate master due to the fact that the binlog on the different intermediate nodes are not guaranteed to be the same.
MariaDB MaxScale's approach
MariaDB MaxScale takes a much simpler approach to the process of being a Binlog Server. It acts as a slave to the real master and as a master to the slaves, in the same way as an intermediate master does. However, it does not implement any re-execution of the statements within the binary log. MariaDB MaxScale creates a local cache of the binary logs it receives from the master and will serve binary log events to the slaves from this cache of the master's binary log. This means that the slaves will always get binary log events that have a one-to-one correlation to those written by the master. Parallelism in the binary log events of the master is maintained in the events that are observed by the slaves.
In the MariaDB MaxScale approach, the latency that is introduced is mostly the added network latency associated with adding the extra network hop. There is no appreciable processing performed at the MariaDB MaxScale level, other than for managing the local cache of the binlog files.
In addition, every MariaDB MaxScale that is acting as a proxy of the master will have exactly the same binlog events as the master itself. This means that a slave can be moved between any of the MariaDB MaxScale server or to the real master without a need to perform any special processing. The result is much simpler behavior for failure recovery and the ability to have a very simple, redundant proxy layer with slaves free to both between the proxies.
Configuring MariaDB MaxScale as a Binlog Server
Using MariaDB MaxScale as a Binlog Server is much the same as using MariaDB MaxScale as a proxy between the clients and the database servers. In this case the master server should be considered as the database backend and the slave servers as the clients of MariaDB MaxScale.
Service Configuration
As with any MariaDB MaxScale configuration a good starting point is with the service definition with the maxscale.cnf file. The service requires a name which is the section name in the ini file, a type parameter with a value of service and the name of the router plugin that should be loaded. In the case of replication proxies this router name is binlogrouter.
[Replication]
type=service
router=binlogrouter
Other standard service parameters need to be given in the configuration section that are used to retrieve the set of users from the backend (master) database, also a version string can be given such that the MariaDB MaxScale instance will report this version string to the slave servers that connect to MariaDB MaxScale.
[Replication]
type=service
router=binlogrouter
version_string=5.6.17-log
user=maxscale
passwd=Mhu87p2D
The user and passwd entries in the above example are used in order for MariaDB MaxScale to populate the credential information that is required to allow the slaves to connect to MariaDB MaxScale. This user should be configured in exactly the same way a for any other MariaDB MaxScale service, i.e. the user needs access to the mysql.user table and the mysql.db table as well as having the ability to perform a SHOW DATABASES command.
This user is the only one available for MySQL connection to MaxScale Binlog Server for administration when master connection is not done yet.
The master server details are currently provided by a master.ini file located in binlog directory and could be changed via CHANGE MASTER TO command issued via MySQL connection to MariaDB MaxScale; refer to the Master setup section below for further details.
In the current implementation of the router only a single server can be used.
The final configuration requirement is the router specific options. The binlog router requires a set of parameters to be passed, these are passed, as a comma separated list of name value pairs, in the router_options parameter of the service definition..
binlogdir
This parameter allows the location that MariaDB MaxScale uses to store binlog files to be set. If this parameter is not set to a directory name then MariaDB MaxScale will store the binlog files in the directory /var/cache/maxscale/. In the binlog dir there is also the 'cache' directory that contains data retrieved from the master during registration phase and the master.ini file which contains the configuration of current configured master.
uuid
This is used to set the unique uuid that the binlog router uses when it connects to the master server. If no explicit value is given for the uuid in the configuration file then a uuid will be generated.
server-id
As with uuid, MariaDB MaxScale must have a unique server-id for the connection it makes to the master, this parameter provides the value of server-id that MariaDB MaxScale will use when connecting to the master.
master-id
The server-id value that MariaDB MaxScale should use to report to the slaves that connect to MariaDB MaxScale. This may either be the same as the server-id of the real master or can be chosen to be different if the slaves need to be aware of the proxy layer. The real master server-id will be used if the option is not set.
master_uuid
It is a requirement of replication that each slave have a unique UUID value. The MariaDB MaxScale router will identify itself to the slaves using the uuid of the real master if this option is not set.
master_version
The MariaDB MaxScale router will identify itself to the slaves using the server version of the real master if this option is not set.
master_hostname
The MariaDB MaxScale router will identify itself to the slaves using the server hostname of the real master if this option is not set.
user
This is the user name that MariaDB MaxScale uses when it connects to the master. This user name must have the rights required for replication as with any other user that a slave uses for replication purposes. If the user parameter is not given in the router options then the same user as is used to retrieve the credential information will be used for the replication connection, i.e. the user in the service entry.
This user is also the only one available for Binlog Server administration when the connection with master is not ready yet: the 'master.ini' file doesn't exists and no other users are available for authentication.
The user that is used for replication, either defined using the user= option in the router options or using the username and password defined of the service must be granted replication privileges on the database server.
MariaDB> CREATE USER 'repl'@'maxscalehost' IDENTIFIED by 'password';
MariaDB> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'maxscalehost';
password
The password of the above user. If the password is not explicitly given then the password in the service entry will be used. For compatibility with other username and password definitions within the MariaDB MaxScale configuration file it is also possible to use the parameter passwd=.
heartbeat
This defines the value of the heartbeat interval in seconds for the connection to the master. MariaDB MaxScale requests the master to ensure that a binlog event is sent at least every heartbeat period. If there are no real binlog events to send the master will sent a special heartbeat event. The default value for the heartbeat period is every 5 minutes. The current interval value is reported in the diagnostic output.
send_slave_heartbeat
This defines whether (on | off) MariaDB MaxScale sends to the slave the heartbeat packet when there are no real binlog events to send. The default value if 'off', no heartbeat event is sent to slave server. If value is 'on' the interval value (requested by the slave during registration) is reported in the diagnostic output and the packet is send after the time interval without any event to send.
burstsize
This parameter is used to define the maximum amount of data that will be sent to a slave by MariaDB MaxScale when that slave is lagging behind the master. In this situation the slave is said to be in "catchup mode", this parameter is designed to both prevent flooding of that slave and also to prevent threads within MariaDB MaxScale spending disproportionate amounts of time with slaves that are lagging behind the master. The burst size can be defined in Kb, Mb or Gb by adding the qualifier K, M or G to the number given. The default value of burstsize is 1Mb and will be used if burstsize is not given in the router options.
transaction_safety
This parameter is used to enable/disable incomplete transactions detection in binlog router. When MariaDB MaxScale starts an error message may appear if current binlog file is corrupted or an incomplete transaction is found. During normal operations binlog events are not distributed to the slaves until a COMMIT is seen. The default value is off, set transaction_safety=on to enable the incomplete transactions detection.
semisync
This parameter controls whether binlog server could ask Master server to start the Semi-Synchronous replication. In order to get semi-sync working the Master server must have the rpl_semi_sync_master plugin installed. The available plugin and the value of GLOBAL VARIABLE rpl_semi_sync_master_enabled are checked in the Master registration phase: if plugin is installed in the Master database the binlog server then requests the semi-sync option. Note:
- the network replication stream from Master has two additional bytes before each binlog event.
- the Semi-Sync protocol requires an acknoledge packet to be sent back to Master only when requested: the semi-sync flag will have value of 1. This flag is set only if rpl_semi_sync_master_enabled=1 in the Master, otherwise it will always have value of 0 and no ack packet is sent back.
Please note that semi-sync replication is only related to binlog server to Master communication.
ssl_cert_verification_depth
This parameter sets the maximum length of the certificate authority chain that will be accepted. Legal values are positive integers. This applies to SSL connection to master server that could be acivated either by writing options in master.ini or later via CHANGE MASTER TO. This parameter cannot be modified at runtime, default is 9.
A complete example of a service entry for a binlog router service would be as follows.
[Replication]
type=service
router=binlogrouter
servers=masterdb
version_string=5.6.17-log
user=maxscale
passwd=Mhu87p2D
router_options=uuid=f12fcb7f-b97b-11e3-bc5e-0401152c4c22,server-id=3,user=repl,password=slavepass,master-id=1,heartbeat=30,binlogdir=/var/binlogs,transaction_safety=1,master_version=5.6.19-common,master_hostname=common_server,master_uuid=xxx-fff-cccc-common,master-id=999,mariadb10-compatibility=1,ssl_cert_verification_depth=9,semisync=1
The minimum set of router options that must be given in the configuration are are server-id and master-id, default values may be used for all other options.
Listener Section
As per any service in MariaDB MaxScale a listener section is required to define the address, port and protocol that is used to listen for incoming connections. Those incoming connections will originate from the slave servers or from a MySQL client in order to administer/configure the master server configuration via SQL commands such as STOP/START SLAVE and CHANGE MASTER TO ...
[Replication Listener]
type=listener
service=Replication
protocol=MySQLClient
port=5308
The protocol used by slaves for connection to MariaDB MaxScale is the same MySQLClient protocol that is used for client applications to connect to databases, therefore the same MariaDB MaxScale protocol module can be used.
It's also possible to enable SSL from clients (MySQL clients or Slave servers) by adding SSL options in the listener, or in a new one:
[Replication Listener_SSL]
type=listener
service=Replication
protocol=MySQLClient
port=5309
ssl=required
ssl_key=/path_to/key.pem
ssl_cert=/path_to/cert.pem
ssl_ca_cert=/path_to/ca-cert.pem
#ssl_version=TLSv10
Check the Configuration-Guide for SSL options details.
MariaDB MaxScale replication diagnostics
The binlog router module of MariaDB MaxScale produces diagnostic output that can be viewed via the maxadmin
client application. Running the maxadmin command and issuing a show service command will produce a considerable amount of output that will show both the master connection status and statistics and also a block for each of the slaves currently connected.
-bash-4.1$ maxadmin show service Replication
Service 0x1567ef0
Service: Replication
Router: binlogrouter (0x7f4ceb96a820)
State: Started
Master connection DCB: 0x15693c0
Master connection state: Binlog Dump
Binlog directory: /var/maxscale/binlogs
Heartbeat period (seconds): 200
Number of master connects: 1
Number of delayed reconnects: 0
Current binlog file: mybin.000061
Current binlog position: 120
Number of slave servers: 0
No. of binlog events received this session: 1002705
Total no. of binlog events received: 2005410
No. of bad CRC received from master: 0
Number of binlog events per minute
Current 5 10 15 30 Min Avg
4 4.0 4.0 4.0 4.0
Number of fake binlog events: 0
Number of artificial binlog events: 61
Number of binlog events in error: 0
Number of binlog rotate events: 60
Number of heartbeat events: 69
Number of packets received: 599
Number of residual data packets: 379
Average events per packet 3347.9
Last event from master at: Thu Jan 29 16:41:53 2015 (10 seconds ago)
Last event from master: 0x1b (Heartbeat Event)
Events received:
Invalid 0
Start Event V3 0
Query Event 703307
Stop Event 55
Rotate Event 65
Integer Session Variable 0
Load Event 0
Slave Event 0
Create File Event 0
Append Block Event 0
Exec Load Event 0
Delete File Event 0
New Load Event 0
Rand Event 0
User Variable Event 0
Format Description Event 61
Transaction ID Event (2 Phase Commit) 299148
Begin Load Query Event 0
Execute Load Query Event 0
Table Map Event 0
Write Rows Event (v0) 0
Update Rows Event (v0) 0
Delete Rows Event (v0) 0
Write Rows Event (v1) 0
Update Rows Event (v1) 0
Delete Rows Event (v1) 0
Incident Event 0
Heartbeat Event 69
Ignorable Event 0
Rows Query Event 0
Write Rows Event (v2) 0
Update Rows Event (v2) 0
Delete Rows Event (v2) 0
GTID Event 0
Anonymous GTID Event 0
Previous GTIDS Event 0
Started: Thu Jan 29 16:06:11 2015
Root user access: Disabled
Backend databases
178.62.50.70:3306 Protocol: MySQLBackend
Users data: 0x156c030
Total connections: 2
Currently connected: 2
If a slave is connected to MaxScale with SSL, an entry will be present in the Slave report:
Slaves:
Server-id: 106
Hostname: SBslave6
Slave UUID: 00019686-7777-7777-7777-777777777777
Slave_host_port: 188.165.213.5:40365
Username: massi
Slave DCB: 0x7fc01be3ba88
Slave connected with SSL: Established
Another Binlog Server diagnostic output comes from SHOW SLAVE STATUS MySQL command
MySQL [(none)]> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Binlog Dump
Master_Host: 88.26.197.94
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.003140
Read_Master_Log_Pos: 16682679
Relay_Log_File: mysql-bin.003140
Relay_Log_Pos: 16682679
Relay_Master_Log_File: mysql-bin.003140
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 16682679
Relay_Log_Space: 16682679
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: Yes
Master_SSL_CA_File: /home/maxscale/packages/certificates/client/ca.pem
Master_SSL_CA_Path:
Master_SSL_Cert: /home/maxscale/packages/certificates/client/client-cert.pem
Master_SSL_Cipher:
Master_SSL_Key: /home/maxscale/packages/certificates/client/client-key.pem
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1111
Master_UUID: 6aae714e-b975-11e3-bc33-0401152c3d01
Master_Info_File: /home/maxscale/binlog/first/binlogs/master.ini
Binlog router compatibility
Binlog Router Plugin is compatible with MySQL 5.6 and MariaDB 5.5, the current default.
In order to use it with MySQL 5.6, the GTID_MODE setting must be OFF and connecting slaves must not use MASTER_AUTO_POSITION = 1 option.
It’s also works with a MariaDB 10.0 setup (master and slaves) but slave connection must not include any GTID feature.
Binlog Router currently does not work for MySQL 5.5 due to missing @@global.binlog_checksum variable.
Master server setup/change
In the MariaDB MaxScale ini file the server section for master is no longer required, same for servers=master_server in the service section. The master server setup is currently managed via CHANGE MASTER TO command issued in MySQL client connection to MariaDB MaxScale or by providing a proper master.ini file in the binlogdir.
If MariaDB MaxScale starts without master.ini there is no replication configured to any master and slaves cannot register to the router: the binlog router could be later configured via CHANGE MASTER TO and the master.ini file will be written.
Please note that is such condition the only user for MySQL protocol connection to MaxScale Binlog Server is the service user.
master.ini file example:
[binlog_configuration]
master_host=127.0.0.1
master_port=3308
master_user=repl
master_password=somepass
filestem=repl-bin
# Master SSL communication options
master_ssl=0
master_ssl_key=/home/mpinto/packages/certificates/client/client-key.pem
master_ssl_cert=/home/mpinto/packages/certificates/client/client-cert.pem
master_ssl_ca=/home/mpinto/packages/certificates/client/ca.pem
#master_tls_version=TLSv12
Enabling replication from a master server requires:
CHANGE MASTER TO MASTER_HOST=‘$master_server’, MASTER_PORT=$master_port, MASTER_USER='repl', MASTER_PASSWORD=‘somepasswd’, MASTER_LOG_FILE=‘repl-bin.000159', MASTER_LOG_POS=4
It's possible to specify the desired MASTER_LOG_FILE but position must be 4
The initfile option is no longer available, filestem option too it's no longer available as the stem is automatically set by parsing MASTER_LOG_FILE.
Stop/start the replication
When router is configured and it is properly working it is possible to stop/start replication:
MariaDB> STOP SLAVE;
...
MariaDB> SHOW SLAVE STATUS;
...
MariaDB> START SLAVE;
Connected or new slave connections are not affected: this STOP/START only controls the the connection to the master and the binlog events receiving.
Change the Master server configuration
When router is configured and it is properly working it is possible to change the master parameters. First step is stop the replication from the master.
MariaDB> STOP SLAVE;
Next step is the master configuration
MariaDB> CHANGE MASTER TO ...
A successful configuration change results in master.ini being updated.
Any error is reported in the MySQL and in log files
The supported options are:
MASTER_HOST
MASTER_PORT
MASTER_USER
MASTER_PASSWORD
MASTER_LOG_FILE
MASTER_LOG_POS
and SSL options as well:
MASTER_SSL (0|1)
MASTER_SSL_CERT (path to certificate file)
MASTER_SSL_KEY (path to key file)
MASTER_SSL_CA (path to CA cerificate file)
MASTER_TLS_VERSION (allowed level of encryption used)
Further details about level of encryption or certificates could be found here Configuration Guuide
There are some constraints related to MASTER_LOG_FILE and MASTER_LOG_POS:
MASTER_LOG_FILE could be changed to next binlog in sequence with MASTER_LOG_POS=4 or to current one at current position.
Examples:
-
Current binlog file is ‘mysql-bin.000003', position 88888
MariaDB> CHANGE MASTER TO MASTER_LOG_FILE=‘mysql-bin.000003',MASTER_LOG_POS=8888
This could be applied to current master_host/port or a new one. If there is a master server maintenance and a slave is being promoted as master it should be checked that binlog file and position are valid: in case of any error replication stops and errors are reported via SHOW SLAVE STATUS and in error logs.
-
Current binlog file is ‘mysql-bin.000099', position 1234
MariaDB> CHANGE MASTER TO MASTER_LOG_FILE=‘mysql-bin.000100',MASTER_LOG_POS=4
This could be applied with current master_host/port or a new one If transaction safety option is on and the current binlog file contains an incomplete transaction it will be truncated to the position where transaction started. In such situation a proper message is reported in MySQL connection and with next START SLAVE binlog file truncation will occur and MariaDB MaxScale will request events from the master using the next binlog file at position 4.
The above scenario might refer to a master crash/failure: the new server that has just been promoted as master doesn't have last transaction events but it should have the new binlog file (the next in sequence). Truncating the previous MariaDB MaxScale binlog is safe as that incomplete transaction is lost. It should be checked that current master or new one has the new binlog file, in case of any error replication stops and errors are reported via SHOW SLAVE STATUS and in error logs.
MariaDB> START SLAVE;
Check for any error in log files and with
MariaDB> SHOW SLAVE STATUS;
In some situations replication state could be STOPPED and proper messages are displayed in error logs and in SHOW SLAVE STATUS,
In order to resolve any mistake done with CHANGE MASTER TO MASTER_LOG_FILE / MASTER_LOG_POS, another administrative command would be helpful.
MariaDB> RESET SLAVE;
This command removes master.ini file, blanks all master configuration in memory and sets binlog router in unconfigured state: a CHANGE MASTER TO command should be issued for the new configuration.
Note: existing binlog files are not touched by this command.
Examples with SSL options:
MySQL [(none)]> CHANGE MASTER TO MASTER_SSL = 1, MASTER_SSL_CERT='/home/maxscale/packages/certificates/client/client-cert.pem', MASTER_SSL_CA='/home/maxscale/packages/certificates/client/ca.pem', MASTER_SSL_KEY='/home/maxscale/packages/certificates/client/client-key.pem', MASTER_TLS_VERSION='TLSv12';
MySQL [(none)]> CHANGE MASTER TO MASTER_TLS_VERSION='TLSv12';
MySQL [(none)]> CHANGE MASTER TO MASTER_SSL = 0;
Some constraints:
- In order to enable/re-enable Master SSL comunication the MASTER_SSL=1 option is required and all certificate options must be explicitey set in the same CHANGE MASTER TO command.
- New certificate options changes take effect after maxScale restart or after MASTER_SSL=1 with the new options.
Note:
- SHOW SLAVE STATUS displays all the options but MASTER_TLS_VERSION value.
- Maxadmin, 'show services' or 'show service $binlog_service' displays all the options when SSL is on.
- STOP SLAVE is required for CHANGE MASTER TO command (any option)
- START SLAVE will use new SSL options for Master SSL communication setup.
Examples: mysql client
MySQL> SHOW SLAVE STATUS\G
Master_SSL_Allowed: Yes
Master_SSL_CA_File: /home/mpinto/packages/certificates/client/ca.pem
Master_SSL_CA_Path:
Master_SSL_Cert: /home/mpinto/packages/certificates/client/client-cert.pem
Master_SSL_Cipher:
Master_SSL_Key: /home/mpinto/packages/certificates/client/client-key.pem
maxadmin client
MaxScale>'show service BinlogServer'
Service: BinlogServer
Router: binlogrouter (0x7fd8c3002b40)
State: Started
Master connection DCB: 0x7fd8c8fce228
Master SSL is ON:
Master SSL CA cert: /home/mpinto/packages/certificates/client/ca.pem
Master SSL Cert: /home/mpinto/packages/certificates/client/client-cert.pem
Master SSL Key: /home/mpinto/packages/certificates/client/client-key.pem
Master SSL tls_ver: TLSv12
Slave servers setup
Examples of CHANGE MASTER TO command issued on a slave server that wants to gets replication events from MariaDB MaxScale binlog router:
CHANGE MASTER TO MASTER_HOST=‘$maxscale_IP’, MASTER_PORT=5308, MASTER_USER='repl', MASTER_PASSWORD=‘somepasswd’,
MASTER_LOG_FILE=‘mysql-bin.000001'
CHANGE MASTER TO MASTER_HOST=‘$maxscale_IP’, MASTER_PORT=5308, MASTER_USER='repl', MASTER_PASSWORD=‘somepasswd’,
MASTER_LOG_FILE=‘mysql-bin.000159', MASTER_LOG_POS=245
The latter example specifies a MASTER_LOG_POS for the selected MASTER_LOG_FILE
Note:
-
MASTER_LOG_FILE must be set to one of existing binlog files in MariaDB MaxScale binlogdir
-
If MASTER_LOG_POS is not set with CHANGE MASTER TO it defaults to 4
-
Latest binlog file name and pos in MariaDB MaxScale could be find via maxadmin output or from mysql client connected to MariaDB MaxScale:
Example:
-bash-4.1$ mysql -h 127.0.0.1 -P 5308 -u$user -p$pass
MySQL [(none)]> show master status\G
*************************** 1. row ***************************
File: mysql-bin.000181
Position: 2569
Enabling MariaDB 10 compatibility
MariaDB 10 has different slave registration phase so an option is required:
router_options=...., mariadb10-compatibility=1
version_string should be modified in order to present MariaDB 10 version when MariaDB MaxScale sends server handshake packet.
version_string=10.0.17-log
New MariaDB events in Diagnostics
With a MariaDB 10 setups new events are displayed when master server is MariaDB 10.
MariaDB 10 Annotate Rows Event 0
MariaDB 10 Binlog Checkpoint Event 0
MariaDB 10 GTID Event 0
MariaDB 10 GTID List Event 0