NDB Cluster Configuration Files Therefore, obtaining an optimum configuration is likely to be an iterative process, the outcome of which can vary widely with the specifics of each NDB Cluster deployment. Changes in configuration are also likely to be indicated when changes are made in the platform on which the cluster is run, or in applications that use the NDB Cluster ’s data. For these reasons, it is not possible to offer a single configuration that is ideal for all usage scenarios. However, in this section, we provide a recommended base configuration. Starting config.ini file.   The following  config.ini  file is a recommended starting point for configuring a cluster running NDB Cluster 8.0: 4057 # TCP PARAMETERS [tcp default] SendBufferMemory=2M ReceiveBufferMemory=2M # Increasing the sizes of these 2 buffers beyond the default values # helps prevent bottlenecks due to slow disk I/O. # MANAGEMENT NODE PARAMETERS [ndb_mgmd default] DataDir= path/to/management/server/data/directory # It is possible to use a different data directory for each management # server, but for ease of administration it is preferable to be # consistent. [ndb_mgmd] HostName= management-server-A-hostname # NodeId= management-server-A-nodeid [ndb_mgmd] HostName= management-server-B-hostname # NodeId= management-server-B-nodeid # Using 2 management servers helps guarantee that there is always an # arbitrator in the event of network partitioning, and so is # recommended for high availability. Each management server must be # identified by a HostName. You may for the sake of convenience specify # a NodeId for any management server, although one is allocated # for it automatically; if you do so, it must be in the range 1-255 # inclusive and must be unique among all IDs specified for cluster # nodes. # DATA NODE PARAMETERS [ndbd default] NoOfReplicas=2 # Using two fragment replicas is recommended to guarantee availability of data; # using only one fragment replica does not provide any redundancy, which means # that the failure of a single data node causes the entire cluster to # shut down. As of NDB 8.0.19, it is also possible (but not required) to # use more than two fragment replicas, although two fragment replicas are # sufficient to provide high availability. LockPagesInMainMemory=1 # On Linux and Solaris systems, setting this parameter locks data node # processes into memory. Doing so prevents them from swapping to disk, # which can severely degrade cluster performance. DataMemory=3456M # The value provided for DataMemory assumes 4 GB RAM # per data node. However, for best results, you should first calculate