Hi, we have a problem with slow synchronization of the configuration, when the cluster node changes and during normal work.

1. Shutting down the cluster node:

   278053:20230329:131439.445 HA manager has been paused
   
   282834:20230329:131439.446 syncing history data in progress...
   
   282838:20230329:131439.558 syncing history data... 100.000000%
   
   282838:20230329:131439.558 syncing history data done
   
   282820:20230329:131440.367 [1] thread stopped [preprocessing worker #1]
   
   282820:20230329:131440.368 [3] thread stopped [preprocessing worker #3]
   
   282820:20230329:131440.368 [2] thread stopped [preprocessing worker #2]
   
   278048:20230329:{+}{color:#FF0000}*131443*{color}{+}.061 syncing trend data...
   
   278048:20230329:{+}*{color:#FF0000}131654{color}*{+}.404 syncing trend data done
   
   278053:20230329:131654.423 HA manager has been stopped
   
   278048:20230329:131655.780 Zabbix Server stopped. Zabbix 6.4.0 (revision 5b2736b6027).
   

1. Turning on the cluster node - only one process is responsible for synchronization

283802:20230329:132044.944 "nodename" node switched to "active" mode

283802:20230329:132044.957 server #0 started [main process]

283942:20230329:132044.958 server #1 started [service manager #1]

283943:20230329:132044.959 server #2 started [configuration syncer #1]

283943:20230329:132058.629 slow query: 13.316544 sec, "select i.itemid,i.hostid,i.status,i.type,i.value_type,i.key_,i.snmp_oid,i.ipmi_sensor,i.delay,i.trapper_hosts,i.logtimefmt,i.params,ir.state,i.authtype,i.username,i.password,i.publickey,i.privatekey,i.flags,i.interfaceid,ir.lastlogsize,ir.mtime,i.history,i.trends,i.inventory_link,i.valuemapid,i.units,ir.error,i.jmx_endpoint,i.master_itemid,i.timeout,i.url,i.query_fields,i.posts,i.status_codes,i.follow_redirects,i.post_type,i.http_proxy,i.headers,i.retrieve_mode,i.request_method,i.output_format,i.ssl_cert_file,i.ssl_key_file,i.ssl_key_password,i.verify_peer,i.verify_host,i.allow_traps,i.templateid,null from items i inner join hosts h on i.hostid=h.hostid join item_rtdata ir on i.itemid=ir.itemid where h.status in (0,1) and i.flags<>2"

283943:20230329:132158.605 slow query: 4.137951 sec, "select itemtagid,itemid,tag,value from item_tag"

283943:20230329:132215.097 slow query: 5.529707 sec, "select triggerid,description,expression,error,priority,type,value,state,lastchange,status,recovery_mode,recovery_expression,correlation_mode,correlation_tag,opdata,event_name,null,null,null,flags from triggers"

284012:20230329:132319.485 server #3 started [alert manager #1] 

1. Standard work

   480:55 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 20.678369 sec, syncing configuration]
   
   481:00 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 24.091629 sec, idle 10 sec]
   
   481:02 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 24.091629 sec, syncing configuration]
   
   481:17 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 24.091629 sec, syncing configuration]
   
   481:22 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 23.483421 sec, idle 10 sec] [alert manager #1|#1][synced configuration in 23.483421 sec, idle 10 sec] 
   

Increased level of configuration syncer logs in the attachment.