Module cartridge.lua-api.failover

get_params ()

Get failover configuration.

(Added in v2.0.2-2)

Returns:

(FailoverParams)

set_params (opts)

Configure automatic failover.

(Added in v2.0.2-2)

Parameters:

• opts:
  • mode: (optional string)
  • state_provider: (optional string)
  • failover_timeout: (optional number) (added in v2.3.0-52)
  • tarantool_params: (optional table)
  • etcd2_params: (optional table) (added in v2.1.2-26)
  • fencing_enabled: (optional boolean) (added in v2.3.0-57)
  • fencing_timeout: (optional number) (added in v2.3.0-57)
  • fencing_pause: (optional number) (added in v2.3.0-57)
  • leader_autoreturn: (optional boolean) (added in v2.7.7)
  • autoreturn_delay: (optional number) (added in v2.7.7)
  • check_cookie_hash: (optional boolean) (added in v2.7.8)

Returns:

(boolean) true if config applied successfully

Or

(nil)

(table) Error description

get_failover_enabled ()

Get current failover state.

(Deprecated since v2.0.2-2)

set_failover_enabled (enabled)

Enable or disable automatic failover.

(Deprecated since v2.0.2-2)

Parameters:

• enabled: (boolean)

Returns:

(boolean) New failover state

Or

(nil)

(table) Error description

promote (replicaset_uuid[, opts])

Promote leaders in replicasets.

Parameters:

• replicaset_uuid: (table) ] = leader_uuid }
• opts:
  • force_inconsistency: (optional boolean) (default: false)
  • skip_error_on_change: (optional boolean) Skip etcd error if vclockkeeper was changed between calls (default: false)

Returns:

(boolean) true On success

Or

(nil)

(table) Error description

pause ()

Stops failover across cluster at runtime. Will be useful in case of “failover storms” when failover triggers too many times in minute.

Returns:

(boolean) true On success

Or

(nil)

(table) Error description

resume ()

Starts failover across cluster at runtime after pause . Don’t forget to resume your failover after pausing it.

Returns:

(boolean) true On success

Or

(nil)

(table) Error description

FailoverParams

Failover parameters.

(Added in v2.0.2-2)

Fields:

• mode: (string) Supported modes are “disabled”, “eventual”, “stateful” or “raft”
• state_provider: (optional string) Supported state providers are “tarantool” and “etcd2”.
• failover_timeout: (number) (added in v2.3.0-52)Timeout (in seconds), used by membership tomark suspect members as dead (default: 20)
• tarantool_params: (added in v2.0.2-2)
  • uri: (string)
  • password: (string)
• etcd2_params: (added in v2.1.2-26)
  • prefix: (string) Prefix used for etcd keys: <prefix>/lock and`<prefix>/leaders`
  • lock_delay: (optional number) Timeout (in seconds), determines lock’s time-to-live (default: 10)
  • endpoints: (optional table) URIs that are used to discover and to access etcd cluster instances.(default: {'http://localhost:2379', 'http://localhost:4001'} )
  • username: (optional string) (default: “”)
  • password: (optional string) (default: “”)
• fencing_enabled: (boolean) (added in v2.3.0-57)Abandon leadership when both the state provider quorum and atleast one replica are lost (suitable in stateful mode only,default: false)
• fencing_timeout: (number) (added in v2.3.0-57)Time (in seconds) to actuate fencing after the check fails(default: 10)
• fencing_pause: (number) (added in v2.3.0-57)The period (in seconds) of performing the check(default: 2)
• leader_autoreturn: (boolean) (added in v2.7.7)If enabled, then switched leader will return after ` autoreturn_delay `(default: false)
• autoreturn_delay: (number) (added in v2.7.7)Time (in seconds) until failover try to return leader to the first nodein ` failover_priority `(default: 300)
• check_cookie_hash: (boolean) (added in v2.7.8)If enabled, then check that nobody else uses this stateboard(default: true)