Percona Cluster

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• access-network | string

  The IP address and netmask of the 'access' network (e.g. 192.168.0.0/24) . This network will be used for access to database services.

• binlogs-expire-days | int

  Default: 10

  Sets the expire_logs_days mysql configuration option, which will make mysql server automatically remove logs older than configured number of days.

• binlogs-max-size | string

  Default: 100M

  Sets the max_binlog_size mysql configuration option, which will limit the size of the binary log files. The server will automatically rotate binlogs after they grow to be bigger than this value. Keep in mind that transactions are never split between binary logs, so therefore binary logs might get larger than configured value.

• binlogs-path | string

  Default: /var/log/mysql/mysql-bin.log

  Location on the filesystem where binlogs are going to be placed. Default mimics what mysql-common package would do for mysql. Make sure you do not put binlogs inside mysql datadir (/var/lib/mysql/)!

• cluster-id | int

  Cluster ID to be used when using MySQL asynchronous replication. . NOTE: This value must be different for each cluster.

• cluster-network | string

  The IP address and netmask of the cluster (replication) network (e.g. 192.168.0.0/24) . This network will be used for wsrep_cluster replication.

• databases-to-replicate | string

  Databases and tables to replicate using MySQL asynchronous replication. The databases should be separated with a semicolon while the tables should be separated with a comma. No tables mean that the whole database will be replicated. For example "database1:table1,table2;database2" will replicate "table1" and "table2" tables from "database1" databasae and all tables from "database2" database. . NOTE: This option should be used only when relating one cluster to the other. It does not affect Galera synchronous replication.

• dataset-size | string

  [DEPRECATED] - use innodb-buffer-pool-size. How much data should be kept in memory in the DB. This will be used to tune settings in the database server appropriately. Supported suffixes include K/M/G/T. If suffixed with %, one will get that percentage of RAM allocated to the dataset.

• dns-ha | boolean

  Use DNS HA with MAAS 2.0. Note if this is set do not set vip settings below.

• enable-binlogs | boolean

  Turns on MySQL binary logs. The placement of the logs is controlled with the binlogs_path config option.

• gcs-fc-limit | int

  This setting controls when flow control engages. Simply speaking, if the wsrep_local_recv_queue exceeds this size on a given node, a pausing flow control message will be sent. The fc_limit defaults to 16 transactions. This effectively means that this is as far as a given node can be behind committing transactions from the cluster.

• ha-bindiface | string

  Default: eth0

  Default network interface on which HA cluster will bind to communication with the other members of the HA Cluster.

• ha-mcastport | int

  Default: 5490

  Default multicast port number that will be used to communicate between HA Cluster nodes.

• harden | string

  Apply system hardening. Supports a space-delimited list of modules to run. Supported modules currently include os, ssh, apache and mysql.

• innodb-buffer-pool-size | string

  By default this value will be set according to 50% of system total memory or 512MB (whichever is lowest) but also can be set to any specific value for the system. Supported suffixes include K/M/G/T. If suffixed with %, one will get that percentage of system total memory allocated.

• innodb-change-buffering | string

  Configure whether InnoDB performs change buffering, an optimization that delays write operations to secondary indexes so that the I/O operations can be performed sequentially. . Permitted values include . none Do not buffer any operations. inserts Buffer insert operations. deletes Buffer delete marking operations; strictly speaking, the writes that mark index records for later deletion during a purge operation. changes Buffer inserts and delete-marking operations. purges Buffer the physical deletion operations that happen in the background. all The default. Buffer inserts, delete-marking operations, and purges. . For more details https://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_change_bufferring

• innodb-file-per-table | boolean

  Default: True

  Turns on innodb_file_per_table option, which will make MySQL put each InnoDB table into separate .idb file. Existing InnoDB tables will remain in ibdata1 file - full dump/import is needed to get rid of large ibdata1 file

• innodb-io-capacity | int

  Configure the InnoDB IO capacity which sets an upper limit on I/O activity performed by InnoDB background tasks, such as flushing pages from the buffer pool and merging data from the change buffer. . This value typically defaults to 200 but can be increased on systems with fast bus-attached SSD based storage to help the server handle the background maintenance work associated with a high rate of row changes. . Alternatively it can be decreased to a minimum of 100 on systems with low speed 5400 or 7200 rpm spindles, to reduce the proportion of IO operations being used for background maintenance work. . For more details https://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_io_capacity

• key | string

  Key ID to import to the apt keyring to support use with arbitrary source configuration from outside of Launchpad archives or PPA's.

• known-wait | int

  Default: 30

  Known wait along with modulo nodes is used to help avoid restart collisions. Known wait is the amount of time between one node executing an operation and another. On slower hardware this value may need to be larger than the default of 30 seconds.

• max-connect-errors | int

  Default: 100

  This setting limits the number of successive unsuccessful connection requests that a host can make to MySQL. After max-connect-errors successive connection requests from a host are interrupted without a successful connection, the MySQL server blocks that host from making further connections. This setting is only for Ubuntu Xenial and newer releases.

• max-connections | int

  Default: 600

  Maximum connections to allow. A value of -1 means use the server's compiled-in default. This is not typically that useful so the charm will configure PXC with a default max-connections value of 600. Note: Connections take up memory resources. Either at startup time with performance-schema=True or during run time with performance-schema=False. This value is a balance between connection exhaustion and memory exhaustion. . Consult a MySQL memory calculator like http://www.mysqlcalculator.com/ to understand memory resources consumed by connections. See also performance-schema.

• min-cluster-size | int

  Minimum number of units expected to exist before charm will attempt to bootstrap percona cluster. If no value is provided this setting is ignored.

• modulo-nodes | int

  This config option is rarely required but is provided for fine tuning, it is safe to leave unset. Modulo nodes is used to help avoid restart collisions as well as distribute load on the cloud at larger scale. During restarts and cluster joins percona needs to execute these operations serially. By setting modulo-nodes to the size of the cluster and known-wait to a reasonable value, the charm will distribute the operations serially. If this value is unset, the charm will check min-cluster-size or else finally default to the size of the cluster based on peer relations. Setting this value to 0 will execute operations with no wait time. Setting this value to less than the cluster size will distribute load but may lead to restart collisions.

• nagios_context | string

  Default: juju

  Used by the nrpe-external-master subordinate charm. A string that will be prepended to instance name to set the host name in nagios. So for instance the hostname would be something like 'juju-myservice-0'. If you are running multiple environments with the same services in them this allows you to differentiate between them.

• nagios_servicegroups | string

  A comma-separated list of nagios service groups. If left empty, the nagios_context will be used as the servicegroup

• nrpe-threads-connected | string

  Default: 80,90

  This configuration option represents the warning and critical percentages that are used to check the number of threads connected to MySQL. The value should be written as a string containing two numbers separated by commas.

• os-access-hostname | string

  The hostname or address of the access endpoint for percona-cluster.

• peer-timeout | string

  This setting sets the gmcast.peer_timeout value. Possible values are documented on the galera cluster site http://galeracluster.com/documentation-webpages/galeraparameters.html For very busy clouds or in resource restricted environments this value can be changed. WARNING Please read all documentation before changing the default value which may have unintended consequences. It may be necessary to set this value higher during deploy time (PT15S) and subsequently change it back to the default (PT3S) after deployment.

• performance-schema | boolean

  The performance schema attempts to automatically size the values of several of its parameters at server startup if they are not set explicitly. When set to on (True) memory is allocated at startup time. The implications of this is any memory related charm config options such as max-connections and innodb-buffer-pool-size must be explicitly set for the environment percona is running in or percona may fail to start. Default to off (False) at startup time giving 5.5 like behavior. The implication of this is one can set configuration values that could lead to memory exhaustion during run time as memory is not allocated at startup time.

• prefer-ipv6 | boolean

  If True enables IPv6 support. The charm will expect network interfaces to be configured with an IPv6 address. If set to False (default) IPv4 is expected. . NOTE: these charms do not currently support IPv6 privacy extension. In order for this charm to function correctly, the privacy extension must be disabled and a non-temporary address must be configured/available on your network interface.

• pxc-strict-mode | string

  Default: enforcing

  Configures pxc_strict_mode (https://www.percona.com/doc/percona-xtradb-cluster/LATEST/features/pxc-strict-mode.html) Valid values are 'disabled', 'permissive', 'enforcing' and 'master.' Defaults to 'enforcing', as this is what PXC5.7 on bionic (and above) does. This option is ignored on PXC < 5.7 (xenial defaults to 5.6, trusty defaults to 5.5)

• root-password | string

  Root account password for new cluster nodes. Overrides the automatic generation of a password for the root user, but must be set prior to deployment time to have any effect.

• source | string

  Repository from which to install. May be one of the following: distro (default), ppa:somecustom/ppa, a deb url sources entry, or a supported Ubuntu Cloud Archive e.g. . cloud:<series>-<openstack-release> cloud:<series>-<openstack-release>/updates cloud:<series>-<openstack-release>/staging cloud:<series>-<openstack-release>/proposed . See https://wiki.ubuntu.com/OpenStack/CloudArchive for info on which cloud archives are available and supported.

• sst-method | string

  Default: xtrabackup-v2

  Percona method for taking the State Snapshot Transfer (SST), can be: 'rsync', 'xtrabackup', 'xtrabackup-v2', 'mysqldump', 'skip' - see https://www.percona.com/doc/percona-xtradb-cluster/5.5/wsrep-system-index.html#wsrep_sst_method

• sst-password | string

  SST account password for new cluster nodes. Overrides the automatic generation of a password for the sst user, but must be set prior to deployment time to have any effect.

• table-open-cache | int

  Default: 2048

  Sets table_open_cache (formerly known as table_cache) to mysql.

• tuning-level | string

  Default: safest

  Valid values are 'safest', 'fast', and 'unsafe'. If set to 'safest', all settings are tuned to have maximum safety at the cost of performance. 'fast' will turn off most controls, but may lose data on crashes. 'unsafe' will turn off all protections but this may be OK in clustered deployments.

• vip | string

  Virtual IP to use to front Percona XtraDB Cluster in active/active HA configuration

• vip_cidr | int

  Default: 24

  Netmask that will be used for the Virtual IP.

• vip_iface | string

  Default: eth0

  Network interface on which to place the Virtual IP.

• wait-timeout | int

  Default: -1

  The number of seconds the server waits for activity on a noninteractive connection before closing it. -1 means use the server's compiled in default.

• wsrep-slave-threads | int

  Specifies the number of threads that can apply replication transactions in parallel. Galera supports true parallel replication that applies transactions in parallel only when it is safe to do so. When unset defaults to 48 for >= Bionic or 1 for <= Xenial.