Shulou(Shulou.com)05/31 Report--

This article introduces the knowledge of "how to configure main loop in CTDB". In the operation of actual cases, many people will encounter such a dilemma. Next, let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Main_loop

Kill-o daemon is still running

Ping local daemon

If election_timeout out

Get debug_level

Get relevant tunables

Get runstate

Get recovery lock file from the server

Get nodemap

Flags

If self_ban

If stop banned frozen

Retrieve capabilities from all connected nodes

Validate_recovery_master-- > force_election

Verify ip public ip {

Ips.pnn = = self & & dont have ip

Ips.pnn! = self & & have ip

} tell recmaster takeover_run

Down here only run with recmaster

Flags right

Active nodes agree we are recmaster-- > force_election get vnnmap

Need recovery-- > do_recovery

Verify all active nodes not in recover mode-- > do_recovery

Hold recovery lock-- > do_recovery

Get remote_nodemaps-- > do_recovery

Num_lmasters

Vnnmap- > size! = num_lmasters-- > do_recovery

Nodemap node also in vnnmap-- > do_recovery

All nodes have same vnnmap

If need_takeover_run do_takeover_run

Force_electionelection_handler

Rec = self ctdb = rec- > ctdb

Pnn = = self out

Ctdb_election_win

States

Longest running

Biggest pnn

Release recover lock file

Let recmaster = that

# do_recovery > we are rec > need_recovery = true > begin > self_ban > recover_lock_file F_SETLK: F_WRLCK > get list of all databases dbmap > create missing local db > create missing remote db > update use same lock files > [db_recovery_parallel] (# db_recovery_parallel) > [do_takeover_run] (# do_takeover_run) > send message reconfigured > need_recovery = false > end > wait rerecovery_timeout

Db_recovery_parallel

Envvar CTDB_RECOVERY_HELPER

Dir CTDB_HELPER_BINDIR = / usr/libexec/ctdb/

File ctdb_recovery_helper

Pipe libsocket

Args [0] = fd [1]

Args [1] = daemon.name = CTDB_SOCKET = / var/run/ctdb/ctdb.socket

Args [2] = random! = 1

Exec/ usr/libexec/ctdb/ctdb_recovery_helper

1 1 / var/run/ctdb/ctdbd.socket 2

Do_takeover_run

Is_in_progress done

Begin

Srvid = 0 pnn =-1

List_of_connected_nodes

Disable takeover_runs 60s

Ctdb_takeover_run

Reenable takeover_runs

Ok

End

Ctdb_takeover_run

Allocate memory for ipalloc_state, including an array of each node

Ip allocation algorithm filled with ipalloc_state

Populate the ipalloc_state NoIPFailback parameter locally-this is a true cluster-wide configuration, and only master uses this value

Fetch the NoIPTakeover and NoIPHostOnAllDisabled of all connected nodes-this action is performed separately, so it can be forged during unit testing

NoIPTakover populated with ipalloc_state

Populate the NoIPHost of ipalloc_state to derive nodes flags and NoIPHostOnAllDisabled

Retrieve and populate the list of IP known and available to ipalloc_state

If no IP address is available, exit early

Build list (known IPs, currently specified node)

Populate the node list to force rebalancing-there is currently no way to obtain the internal structure, only nodes with new IP addresses have been added using the LCP2 algorithm

Run the IP allocation algorithm

Send RELEASE_IP to all nodes to cancel undeserved ips

Configurations that send TAKE_IP to all nodes should have ips

Send IPREALLOCATED all nodes (backward compatible hack)

Ipalloc_state_init

Three algorithms ipalloc_lcp2 = = > default

Ipalloc_deterministic = > pnn= I% numnodes ipalloc_nondeterministic = = > min is based on pnn=0 and polls existing ip

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.