
msgid "Monitoring a replica set"
msgstr ""

msgid ""
"To learn what instances belong in the replica set, and obtain statistics for"
" all these instances, issue a "
":doc:`/reference/reference_lua/box_info/replication` request:"
msgstr ""

msgid ""
"tarantool> box.info.replication\n"
"---\n"
"  replication:\n"
"    1:\n"
"      id: 1\n"
"      uuid: b8a7db60-745f-41b3-bf68-5fcce7a1e019\n"
"      lsn: 88\n"
"    2:\n"
"      id: 2\n"
"      uuid: cd3c7da2-a638-4c5d-ae63-e7767c3a6896\n"
"      lsn: 31\n"
"      upstream:\n"
"        status: follow\n"
"        idle: 43.187747001648\n"
"        peer: replicator@192.168.0.102:3301\n"
"        lag: 0\n"
"      downstream:\n"
"        vclock: {1: 31}\n"
"    3:\n"
"      id: 3\n"
"      uuid: e38ef895-5804-43b9-81ac-9f2cd872b9c4\n"
"      lsn: 54\n"
"      upstream:\n"
"        status: follow\n"
"        idle: 43.187621831894\n"
"        peer: replicator@192.168.0.103:3301\n"
"        lag: 2\n"
"      downstream:\n"
"        vclock: {1: 54}\n"
"..."
msgstr ""

msgid ""
"This report is for a master-master replica set of three instances, each "
"having its own instance id, UUID and log sequence number."
msgstr ""

msgid ""
"The request was issued at master #1, and the reply includes statistics for "
"the other two masters, given in regard to master #1."
msgstr ""

msgid "The primary indicators of replication health are:"
msgstr ""

msgid ""
":ref:`idle <box_info_replication_upstream_idle>`, the time (in seconds) "
"since the instance received the last event from a master."
msgstr ""

msgid ""
"A master sends heartbeat messages to a replica every second, and the master "
"is programmed to disconnect if it does not see acknowledgments of the "
"heartbeat messages within :ref:`replication_timeout <cfg_replication-"
"replication_timeout>` * 4 seconds."
msgstr ""

msgid ""
"Therefore, in a healthy replication setup, ``idle`` should never exceed "
"``replication_timeout``: if it does, either the replication is lagging "
"seriously behind, because the master is running ahead of the replica, or the"
" network link between the instances is down."
msgstr ""

msgid ""
":ref:`lag <box_info_replication_upstream_lag>`, the time difference between "
"the local time at the instance, recorded when the event was received, and "
"the local time at another master recorded when the event was written to the "
":ref:`write ahead log <internals-wal>` on that master."
msgstr ""

msgid ""
"Since the ``lag`` calculation uses the operating system clocks from two "
"different machines, do not be surprised if it’s negative: a time drift may "
"lead to the remote master clock being consistently behind the local "
"instance's clock."
msgstr ""

msgid "For multi-master configurations, ``lag`` is the maximal lag."
msgstr ""
