Shulou(Shulou.com)06/01 Report--

The Primary and Standby of DB2 detect the existence of each other by sending a heartbeat signal.

Several db2pd-db xxx-hadr monitoring indicators related to this heartbeat

HEARTBEAT_INTERVAL (seconds) = 30

HEARTBEAT_MISSED = 0

HEARTBEAT_EXPECTED = 58588

HADR_TIMEOUT (seconds) = 120

What you need to look at is the ratio of HEARTBEAT_MISSED/HEARTBEAT_EXPECTED

HADR_TIMEOUT is a parameter of DB CFG, which is set to 120 here.

HEARTBEAT_INTERVAL calculation method: HADR_TIMEOUT/4 = 120pm 44030

The maximum value of HEARTBEAT_INTERVAL is 30 seconds

The recommended hadr_timeout parameter setting is at least 60 seconds.

The recommended value of HADR_TIMEOUT is 120 seconds. After calculation, the HEARTBEAT_INTERVAL is 30 seconds.

Network stability and machine response time should be taken into account when setting hadr_timeout parameters. If the network has irregular or long transmission delays, a longer timeout setting should be used.

For each heartbeat, a PEER_WINDOW_ end value is generated on the Primal side and sent to the Standard side.

If the Primary side fails before PEER_WINDOW_END, you can perform a failover without data loss (the TAKEOVER BY FORCE command adds a PEER WINDOW ONLY option)

Hadr_peer_window settings > = response time + margin of safety + heartbeat interval

Where:

Response time = estimated time that the automation software detects the failure and invokes the HADR takeover

Margin of safety = 5 seconds, margin of safety of clock synchronization between primary and standby machines

Heartbeat interval = MIN (hadr_ timeout value / 4 minutes Hadrow peer _ window value / 4 minutes 30 seconds)

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.