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xSQL Cluster Parameters

The xSQL configuration file can be used to define eXtremeDB Cluster parameters corresponding to the C API mco_cluster_params_t structure.

For an overview see page Configuration File Parameters

The cluster_params section consists of a set of "name : value" pairs enclosed within braces. For example:
 
    cluster_params : {
        mem_page_size : 256,
        nodes : [
            {
                addr : "127.0.0.1:5000",
                qrank : 0
            },
        ],
        node_id : 0,
        ...
    }
     
The following table lists the possible options for the cluster_params section with the corresponding C API structures and values specified in the comment:
Option name : example value Comment
nodes : [ { ...} ]
List (array) of cluster nodes (mco_cluster_node_params_t.addr and mco_cluster_node_params_t.qrank)
     
    nodes : [
    {
        # Node address in form <IP/hostname>:<port> (mco_cluster_node_params_t::addr)
        addr : "127.0.0.1:5000",
         
        # Quorum rank (mco_cluster_node_params_t::qrank), unsigned
        qrank : 0
    },
    ]
 
node_id : 0, Current node ID (mco_cluster_params_t::node_id), unsigned

conn_pool_factor: 50, Size of connection pool in percents of db_max_connections (mco_cluster_params_t::conn_pool_factor)

n_listener_threads : 5, The number of cluster listener threads. Default value is 1; larger values allow to increase performance while handling remote transactions

sync_msg_objects : 100, Max number of objects per message during synchronization (mco_cluster_params_t::sync_msg_objects), unsigned

sync_msg_size : 100k, Max size of message in bytes during synchronization (mco_cluster_params_t::sync_msg_size), unsigned
window : {...}
Transaction window parameters (mco_cluster_params_t::window)
     
    window : {
        # Size of window buffer in bytes (mco_cluster_window_t::bsize), unsigned
        bsize : 100k
         
        # Number of transactions (mco_cluster_window_t::length), unsigned
        length : 4,
         
        # Window timeout in milliseconds (mco_cluster_window_t::timeout), unsigned
        timeout : 10,
    },
 
cl_sndbuf : 2k, Internal send buffer size in bytes (mco_cluster_params_t::cl_sndbuf), unsigned

cl_rcvbuf : 2k, Internal receive buffer size in bytes (mco_cluster_params_t::cl_rcvbuf), unsigned

mode_mask : binary_evolution,
Cluster mode mask (mco_cluster_params_t::mode_mask), combination of

binary_evolution (MCO_CLUSTER_MODE_BINARY_EVOLUTION) and

early_data_send (MCO_CLUSTER_MODE_EARLY_DATA_SEND)

quorum_policy : qrank_based,
Custom quorum policies. Possible values are :

qrank_based - default policy based on node's qrank;

always_writable - allows WRITE transactions on the node regardless of state of other nodes

all_nodes_required - WRITE transactions are allowed only if all other nodes are alive and connected to the current node

auto_detach : true, Detach node from cluster on exit, boolean. Default value is false

ssl_params : {...} Cluster-specific SSL settings. See the global ssl_params section for the description of the parameters and their default values. These parameters override the global settings. To inherit the global ssl_params settings, leave the ssl_params section empty. (They have the same parameters and default values as the global section, except for ca_path and ca_file, which are only allowed in the global section.)
nw_tcp : {...}
TCP/IP parameters (mco_cluster_params_t::nw::tcp)
     
    nw_tcp : {
        # Maximum socket send buffer in bytes (mco_clnw_tcp_params_t::so_sndbuf), unsigned
        so_sndbuf : 16k,
         
        # Maximum socket receive buffer in bytes (mco_clnw_tcp_params_t::so_rcvbuf), unsigned
        so_rcvbuf : 16k,
         
        # Timeout for connecting nodes to each other in milliseconds
        # (mco_clnw_tcp_params_t::connect_timeout), unsigned
        connect_timeout : 5000,
         
        # Time between attempts to connect to other nodes in milliseconds
        # (mco_clnw_tcp_params_t::connect_interval), unsigned
        connect_interval : 500,
         
        # Number of milliseconds between keep-alive messages in milliseconds
        # (mco_clnw_tcp_params_t::keepalive_time), unsigned
        keepalive_time : 1000,
         
        # Number of keep-alive probes to send before node disconnects
        # (mco_clnw_tcp_params_t::keepalive_probes), unsigned
        keepalive_probes : 5,
         
        # The level of compression: 0 = no compression; 1 = best speed, 
        # 9 - best compression. Default value is 0							
        compression_level : 9,
         
        # mco_clnw_tcp_params_t::socket_domain, one of
        # 'inet' (MCO_SOCK_INET_DOMAIN), 'local' (MCO_SOCK_LOCAL_DOMAIN) or
        # 'sdp' (MCO_SOCK_SDP_DOMAIN)
        socket_domain : inet,
    },
 
nw_mpi : {...}
MPI parameters (mco_cluster_params_t::nw::mpi)
     
    nw_mpi : {
        # MPI mode flags (mco_clnw_mpi_params_t::flags). combination of
        # 'busywait' (MCO_CLUSTER_MPI_BUSYWAIT) and
        # 'serialized_send' (MCO_CLUSTER_MPI_SERIALIZED_SEND)
        flags : busywait
    },
 

Option name : example value	Comment
nodes : [ { ...} ]	List (array) of cluster nodes (`mco_cluster_node_params_t.addr` and `mco_cluster_node_params_t`.`qrank`) nodes : [ { # Node address in form <IP/hostname>:<port> (mco_cluster_node_params_t::addr) addr : "127.0.0.1:5000", # Quorum rank (mco_cluster_node_params_t::qrank), unsigned qrank : 0 }, ]
node_id : 0,	Current node ID (`mco_cluster_params_t::node_id`), unsigned
conn_pool_factor: 50,	Size of connection pool in percents of `db_max_connections` (`mco_cluster_params_t::conn_pool_factor`)
n_listener_threads : 5,	The number of cluster listener threads. Default value is 1; larger values allow to increase performance while handling remote transactions
sync_msg_objects : 100,	Max number of objects per message during synchronization (`mco_cluster_params_t::sync_msg_objects`), unsigned
sync_msg_size : 100k,	Max size of message in bytes during synchronization (`mco_cluster_params_t::sync_msg_size`), unsigned
window : {...}	Transaction window parameters (`mco_cluster_params_t::window`) window : { # Size of window buffer in bytes (mco_cluster_window_t::bsize), unsigned bsize : 100k # Number of transactions (mco_cluster_window_t::length), unsigned length : 4, # Window timeout in milliseconds (mco_cluster_window_t::timeout), unsigned timeout : 10, },
cl_sndbuf : 2k,	Internal send buffer size in bytes (`mco_cluster_params_t::cl_sndbuf`), unsigned
cl_rcvbuf : 2k,	Internal receive buffer size in bytes (`mco_cluster_params_t::cl_rcvbuf`), unsigned
mode_mask : binary_evolution,	Cluster mode mask (`mco_cluster_params_t::mode_mask`), combination of `binary_evolution` (`MCO_CLUSTER_MODE_BINARY_EVOLUTION`) and `early_data_send` (`MCO_CLUSTER_MODE_EARLY_DATA_SEND`)
quorum_policy : qrank_based,	Custom quorum policies. Possible values are : `qrank_based` - default policy based on node's qrank; `always_writable` - allows WRITE transactions on the node regardless of state of other nodes `all_nodes_required` - WRITE transactions are allowed only if all other nodes are alive and connected to the current node
auto_detach : true,	Detach node from cluster on exit, boolean. Default value is `false`
ssl_params : {...}	Cluster-specific SSL settings. See the global `ssl_params` section for the description of the parameters and their default values. These parameters override the global settings. To inherit the global `ssl_params` settings, leave the `ssl_params` section empty. (They have the same parameters and default values as the global section, except for `ca_path` and `ca_file`, which are only allowed in the global section.)
nw_tcp : {...}	TCP/IP parameters (`mco_cluster_params_t::nw::tcp`) nw_tcp : { # Maximum socket send buffer in bytes (mco_clnw_tcp_params_t::so_sndbuf), unsigned so_sndbuf : 16k, # Maximum socket receive buffer in bytes (mco_clnw_tcp_params_t::so_rcvbuf), unsigned so_rcvbuf : 16k, # Timeout for connecting nodes to each other in milliseconds # (mco_clnw_tcp_params_t::connect_timeout), unsigned connect_timeout : 5000, # Time between attempts to connect to other nodes in milliseconds # (mco_clnw_tcp_params_t::connect_interval), unsigned connect_interval : 500, # Number of milliseconds between keep-alive messages in milliseconds # (mco_clnw_tcp_params_t::keepalive_time), unsigned keepalive_time : 1000, # Number of keep-alive probes to send before node disconnects # (mco_clnw_tcp_params_t::keepalive_probes), unsigned keepalive_probes : 5, # The level of compression: 0 = no compression; 1 = best speed, # 9 - best compression. Default value is 0 compression_level : 9, # mco_clnw_tcp_params_t::socket_domain, one of # 'inet' (MCO_SOCK_INET_DOMAIN), 'local' (MCO_SOCK_LOCAL_DOMAIN) or # 'sdp' (MCO_SOCK_SDP_DOMAIN) socket_domain : inet, },
nw_mpi : {...}	MPI parameters (`mco_cluster_params_t::nw::mpi`) nw_mpi : { # MPI mode flags (mco_clnw_mpi_params_t::flags). combination of # 'busywait' (MCO_CLUSTER_MPI_BUSYWAIT) and # 'serialized_send' (MCO_CLUSTER_MPI_SERIALIZED_SEND) flags : busywait },