MySQL Fabric Setup using ndb Cluster
By Rudrap-Oracle on Apr 28, 2014
MySQL SystemQA: MySQL Fabric Setup using ndb Cluster
MySQL Fabric is an open-source solution released by the MySQL Engineering team at Oracle. It is an extensible and easy to use system for managing a MySQL deployment for Sharding and High-availability. To ensure/provide resilience to failures, MySQL Fabric manages servers in groups and deploy High Availability. MySQL Fabric also supports Sharding, which is used to scale out a large databases. Sharding setup handles the increasing demand for read loads and also handles the increasing write loads. The database/table are shared across different servers, where each shard contain a fragment of the data. A Fabric node is Fabric Process + State Store (which is a MySQL Server).As MySQL Fabric manages such a valuable information for server farms and scaling of database, using single machine to handle the MySQL Fabric node is not a good solution. Thus we need to come up with a solution that make MySQL Fabric node fail-safe. We need to have a full-fledged fault-tolerant solution at both levels, i.e. process and state store. Here we will only discuss redundancy at the state store level and a full-fledged solution is something that will be delivered in the future. We can use two methods to make MySQL Fabric resilient with no single point of failure EITHER using MySQL Replication setup with multiple Fabric nodes in a topology OR setting up fabric nodes using MySQL Cluster (ndb cluster).As part of SystemQA team at Oracle MySQL we validated both possibilities to make MySQL Fabric failure-safe. As part of SystemQA team at Oracle MySQL we validated both possibilities to make MySQL Fabric resilient with no single point of failure.
What we did?
- Prepared a ndb cluster setup in multiple machines - MySQL Fabric Setup and Start in a cluster node. - Killed/Crashed the Fabric node/server and verified if the data is safe in other cluster nodes. - Start Fabric node in other cluster node and run the application.
With its distributed, shared-nothing architecture, MySQL Cluster has been carefully designed
to deliver 99.999% availability ensuring resilience to failures and the ability to perform
scheduled maintenance without downtime.
Shared Nothing Architecture, No Single Point of Failure
NDB Cluster Setup in Multi Machines:
1) in mngmt machine create the folders -bash-4.1$ /usr/local/mysql/ data/ mgmt_data/ mysql-cluster/ 2) in mngmt machine create the ini file -bash-4.1$ ls /usr/local/mysql/mgmt_data/ mgmt_config.ini --------------------------------- [ndbd default] NoOfReplicas = 2 [mysqld default] [ndb_mgmd default] [tcp default] [ndb_mgmd] NodeId = 1 HostName = mngmt_machine_ip #LogDestination = FILE:filename=/usr/local/mysql/log/ndb_1_cluster.log,maxsize=1000000, maxfiles=6 [ndbd] NodeId = 2 HostName = mngmt_machine_ip DataDir = /..../data [ndbd] NodeId = 4 HostName = othernodemahcine_ip DataDir = /..../data [mysqld] NodeId = 3 [mysqld] NodeId = 5 --------------------------------------- 3) create /etc/my.cnf (different port and socket) in both machines [MYSQLD] ndbcluster ndb-connectstring=mngmt_machine_ip [MYSQL_CLUSTER] ndb-connectstring=mngmt_machine_ip [client] port=13000 socket=/tmp/mysql13000.sock [mysqld] port=13000 socket=/tmp/mysql13000.sock key_buffer_size=16M max_allowed_packet=8M default-storage-engine = ndb [mysqldump] quick 4) start the MGM node process in mngmt machine: /..../mysql-cluster-binary/bin/ndb_mgmd --config-file=/usr/local/mysql/mgmt_data/ mgmt_config.ini --initial /..../mysql-cluster-binary/bin/ndbd --initial 5) On each of the DATA (NDB) nodes, run this command to start ndbd only for the first time: /..../mysql-cluster-binary/bin//ndbd --initial -c mngmt_ip:port in all nodes run ps -ef |grep ndbd and check if nodes are running #Note that it is very important to use the --initial parameter only when starting ndbd for the first time, or when restarting after a backup/restore operation or a configuration change. This is because the --initial option causes the node to delete any files created by earlier ndbd instances that are needed for recovery, including the recovery log files. 6) Start mysql servers in different nodes. 7) Use the mngmt machine to check whether the cluster is working properly. ndb_mgm ndb_mgm> show make sure that all nodes are connected.
/usr/bin/mysqlfabric --param=storage.address=localhost :13000 –param=storage.user=root --param=protocol.xmlrpc .password=<password> manage setup /usr/bin/mysqlfabric --param=storage.address=localhost :13000 –param=storage.user=root --param=protocol.xmlrpc .password=<password> manage start
Manual recovery of fabric state-store if there is a fabric cluster node failure.
Crash and restart of Cluster node (fabric node) to ensure recovery of fabric state-store.