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HAST.CONF(5) BSD File Formats Manual HAST.CONF(5) NAME hast.conf -- configuration file for the hastd(8) daemon and the hastctl(8) utility. DESCRIPTION The hast.conf file is used by both hastd(8) daemon and hastctl(8) control utility. Configuration file is designed in a way that exactly the same file can be (and should be) used on both HAST nodes. Every line starting with # is treated as comment and ignored. CONFIGURATION FILE SYNTAX General syntax of the hast.conf file is following: # Global section control <addr> listen <addr> replication <mode> timeout <seconds> exec <path> on <node> { # Node section control <addr> listen <addr> } on <node> { # Node section control <addr> listen <addr> } resource <name> { # Resource section replication <mode> name <name> local <path> timeout <seconds> exec <path> on <node> { # Resource-node section name <name> # Required local <path> # Required remote <addr> } on <node> { # Resource-node section name <name> # Required local <path> # Required remote <addr> } } Most of the various available configuration parameters are optional. If parameter is not defined in the particular section, it will be inherited from the parent section. For example, if the listen parameter is not de- fined in the node section, it will be inherited from the global section. In case the global section does not define the listen parameter at all, the default value will be used. CONFIGURATION FILE DESCRIPTION The <node> argument can be replaced either by a full hostname as obtained by gethostname(3), only first part of the hostname, or by node's UUID as found in the kern.hostuuid sysctl(8) variable. The following statements are available: control <addr> Address for communication with hastctl(8). Each of the following examples defines the same control address: uds:///var/run/hastctl unix:///var/run/hastctl /var/run/hastctl The default value is uds:///var/run/hastctl. listen <addr> Address to listen on in form of: protocol://protocol-specific-address Each of the following examples defines the same listen address: 0.0.0.0 0.0.0.0:8457 tcp://0.0.0.0 tcp://0.0.0.0:8457 tcp4://0.0.0.0 tcp4://0.0.0.0:8457 The default value is tcp4://0.0.0.0:8457. replication <mode> Replication mode should be one of the following: memsync Report the write operation as completed when local write com- pletes and when the remote node acknowledges the data re- ceipt, but before it actually stores the data. The data on remote node will be stored directly after sending acknowl- edgement. This mode is intended to reduce latency, but still provides a very good reliability. The only situation where some small amount of data could be lost is when the data is stored on primary node and sent to the secondary. Secondary node then acknowledges data receipt and primary reports suc- cess to an application. However, it may happen that the sec- ondary goes down before the received data is really stored locally. Before secondary node returns, primary node dies entirely. When the secondary node comes back to life it be- comes the new primary. Unfortunately some small amount of data which was confirmed to be stored to the application was lost. The risk of such a situation is very small. The memsync replication mode is currently not implemented. fullsync Mark the write operation as completed when local as well as remote write completes. This is the safest and the slowest replication mode. The fullsync replication mode is the de- fault. async The write operation is reported as complete right after the local write completes. This is the fastest and the most dan- gerous replication mode. This mode should be used when replicating to a distant node where latency is too high for other modes. The async replication mode is currently not im- plemented. timeout <seconds> Connection timeout in seconds. The default value is 5. exec <path> Execute the given program on various HAST events. Below is the list of currently implemented events and arguments the given pro- gram is executed with: <path> role <resource> <oldrole> <newrole> Executed on both primary and secondary nodes when resource role is changed. <path> connect <resource> Executed on both primary and secondary nodes when connection for the given resource between the nodes is established. <path> disconnect <resource> Executed on both primary and secondary nodes when connection for the given resource between the nodes is lost. <path> syncstart <resource> Executed on primary node when synchronization process of sec- ondary node is started. <path> syncdone <resource> Executed on primary node when synchronization process of sec- ondary node is completed successfully. <path> syncintr <resource> Executed on primary node when synchronization process of sec- ondary node is interrupted, most likely due to secondary node outage or connection failure between the nodes. <path> split-brain <resource> Executed on both primary and secondary nodes when split-brain condition is detected. The <path> argument should contain full path to executable program. If the given program exits with code different than 0, hastd will log it as an error. The <resource> argument is resource name from the configuration file. The <oldrole> argument is previous resource role (before the change). It can be one of: init, secondary, primary. The <newrole> argument is current resource role (after the change). It can be one of: init, secondary, primary. name <name> GEOM provider name that will appear as /dev/hast/_name_. If name is not defined, resource name will be used as provider name. local <path> Path to the local component which will be used as backend provider for the resource. This can be either GEOM provider or regular file. remote <addr> Address of the remote hastd daemon. Format is the same as for the listen statement. When operating as a primary node this address will be used to connect to the secondary node. When operating as a secondary node only connections from this address will be accepted. A special value of none can be used when the remote address is not yet known (eg. the other node is not set up yet). FILES /etc/hast.conf The default hast.conf configuration file. /var/run/hastctl Control socket used by the hastctl(8) control utility to communicate with the hastd(8) daemon. EXAMPLES The example configuration file can look as follows: resource shared { local /dev/da0 on hasta { remote tcp4://10.0.0.2 } on hastb { remote tcp4://10.0.0.1 } } resource tank { on hasta { local /dev/mirror/tanka remote tcp4://10.0.0.2 } on hastb { local /dev/mirror/tankb remote tcp4://10.0.0.1 } } SEE ALSO gethostname(3), geom(4), hastctl(8), hastd(8). AUTHORS The hast.conf was written by Pawel Jakub Dawidek <pjd@FreeBSD.org> under sponsorship of the FreeBSD Foundation. BSD August 30, 2010 BSD
NAME | DESCRIPTION | CONFIGURATION FILE SYNTAX | CONFIGURATION FILE DESCRIPTION | FILES | EXAMPLES | SEE ALSO | AUTHORS
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