zabbix Aborted connection to db solution

 Unfortunately the people at zabbix are just slaves to making money, an open project is just a way to get hooked and its developers don't address real bugs.

This error is due to one or another parameter that is only found by increasing the level of detail in the log file, here we will give an example of how it could be for https://support.zabbix.com/browse/ZBX-20729 unsolved issue or common forums probles like https://www.zabbix.com/forum/zabbix-troubleshooting-and-problems/440755-zabbix-6-raspbian-warning-aborted-connection-to-db !

This works for Zabbix server or Zabbix proxy both are same, the only difference is that the 

[Warning] Aborted connection to db... 

(Got an error reading communication packets)

The problem is as simple like bad parameters or non valid DB connection, so possible causes (As found in syslog):

1. Rare cases if you put the "Zabbix Server" host measurement to "Disabled", the problem goes away and Zabbix runs fine either Zabbix proxy also.
2. Database connection is not valid, check database connection, reading files /etc/zabbix/zabbix_proxy.conf or /etc/zabbix/zabbix_server.conf both have the same parameters.. if the database connection is denied by the service of the database you must test as the zabbix user if are able to connect or if the user/password are correct
3. A zabbix parameter must be tuned, the zabbix server/proxy is pretty exact on resources so if some parameters are too little will crash and notify inside the log, for that you should increase the log to debug, restart the service and check for errors like the following part of log demostrates:

  5841:20240107:062601.470 End of DCsync_interfaces()
  5841:20240107:062601.470 In DCsync_items()
  5841:20240107:062601.511 End of DCsync_items()
  5841:20240107:062601.511 In DCsync_template_items()
  5841:20240107:062601.511 End of DCsync_template_items()
  5841:20240107:062601.511 In DCsync_prototype_items()
  5841:20240107:062601.511 End of DCsync_prototype_items()
  5841:20240107:062601.511 In DCsync_item_preproc()
  5841:20240107:062601.513 __mem_malloc: skipped 4 asked 48088 skip_min 528 skip_max 13992
  5841:20240107:062601.513 [file:dbconfig.c,line:96] __zbx_mem_realloc(): out of memory (requested 48088 bytes)
  5841:20240107:062601.513 [file:dbconfig.c,line:96] __zbx_mem_realloc(): please increase CacheSize configuration parameter
  5841:20240107:062601.513 === memory statistics for configuration cache ===
  5841:20240107:062601.513 free chunks of size     24 bytes:       14
  5841:20240107:062601.513 free chunks of size     32 bytes:        5
  5841:20240107:062601.513 free chunks of size     40 bytes:        3
  5841:20240107:062601.513 free chunks of size     48 bytes:        3
  5841:20240107:062601.513 free chunks of size     56 bytes:        3
  5841:20240107:062601.513 free chunks of size >= 256 bytes:        4

After we increase the log debug level, we check the log and in this log the key is "out of memory", and just after that line we found the cause, "increase CacheSize configuration parameter".. after do that the server just run.. 

This case was special, each case is special and you should increase the log level to debug and later check into the log file for root causes..