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8 Internal checks

Overview

Internal checks allow to monitor the internal processes of Zabbix. In other words, you can monitor what goes on with Zabbix server or Zabbix proxy.

Internal checks are calculated:

  • on Zabbix server - if the host is monitored by server
  • on Zabbix proxy - if the host is monitored by proxy

Internal checks are processed by server or proxy regardless of host maintenance status.

To use this item, choose the Zabbix internal item type.

Internal checks are processed by Zabbix pollers.

Performance

Using some internal items may negatively affect performance. These items are:

  • zabbix[host,,items]
  • zabbix[host,,items_unsupported]
  • zabbix[hosts]
  • zabbix[items]
  • zabbix[items_unsupported]
  • zabbix[queue]
  • zabbix[requiredperformance]
  • zabbix[stats,,,queue]
  • zabbix[triggers]

The System information and Queue frontend sections are also affected.

Supported checks

  • Parameters without angle brackets are constants - for example, 'host' and 'available' in zabbix[host,<type>,available]. Use them in the item key as is.
  • Values for items and item parameters that are "not supported on proxy" can only be gathered if the host is monitored by server. And vice versa, values "not supported on server" can only be gathered if the host is monitored by proxy.
Key
Description Return value Comments
zabbix[boottime]
Startup time of Zabbix server or Zabbix proxy process in seconds. Integer
zabbix[cluster,discovery,nodes]
Discover high availability cluster nodes. JSON This item can be used in low-level discovery.
zabbix[host,,items]
Number of enabled items (supported and not supported) on the host. Integer This item is supported since Zabbix 3.0.0.
zabbix[host,,items_unsupported]
Number of enabled unsupported items on the host. Integer This item is supported since Zabbix 3.0.0.*
zabbix[host,,maintenance]
Current maintenance status of a host. 0 - host in normal state,
1 - host in maintenance with data collection,
2 - host in maintenance without data collection.
This item is always processed by Zabbix server regardless of host location (on server or proxy). The proxy will not receive this item with configuration data.
The second parameter must be empty and is reserved for future use.
zabbix[host,active_agent,available]
Availability of active agent checks on the host. 0 - unknown, 1 - available, 2 - not available.
zabbix[host,discovery,interfaces]
Details of all configured interfaces of the host in Zabbix frontend. JSON object. This item can be used in low-level discovery.
This item is supported since Zabbix 3.4.0.
(not supported on proxy)
zabbix[host,<type>,available]
Availability of the main interface of a particular type of checks on the host. 0 - not available, 1 - available, 2 - unknown. Valid types are:
agent, snmp, ipmi, jmx

The item value is calculated according to configuration parameters regarding host unreachability/unavailability.

This item is supported since Zabbix 2.0.0.
zabbix[hosts]
Number of monitored hosts. Integer
zabbix[items]
Number of enabled items (supported and not supported). Integer
zabbix[items_unsupported]
Number of not supported items. Integer
zabbix[java,,<param>]
Information about Zabbix Java gateway. If <param> is ping, "1" is returned. Can be used to check Java gateway availability using nodata() trigger function.

If <param> is version, version of Java gateway is returned. Example: "2.0.0".
Valid values for param are:
ping, version

Second parameter must be empty and is reserved for future use.
zabbix[lld_queue]
Count of values enqueued in the low-level discovery processing queue. Integer This item can be used to monitor the low-level discovery processing queue length.

This item is supported since Zabbix 4.2.0.
zabbix[preprocessing_queue]
Count of values enqueued in the preprocessing queue. Integer This item can be used to monitor the preprocessing queue length.

This item is supported since Zabbix 3.4.0.
zabbix[process,<type>,<mode>,<state>]
Time a particular Zabbix process or a group of processes (identified by <type> and <mode>) spent in <state> in percentage. It is calculated for the last minute only.

If <mode> is Zabbix process number that is not running (for example, with 5 pollers running <mode> is specified to be 6), such an item will turn into unsupported state.
Minimum and maximum refers to the usage percentage for a single process. So if in a group of 3 pollers usage percentages per process were 2, 18 and 66, min would return 2 and max would return 66.
Processes report what they are doing in shared memory and the self-monitoring process summarizes that data each second. State changes (busy/idle) are registered upon change - thus a process that becomes busy registers as such and doesn't change or update the state until it becomes idle. This ensures that even fully hung processes will be correctly registered as 100% busy.
Currently, "busy" means "not sleeping", but in the future additional states might be introduced - waiting for locks, performing database queries, etc.
On Linux and most other systems, resolution is 1/100 of a second.
Percentage of time.
Float
Supported types of server processes:
alert manager, alert syncer, alerter, availability manager, configuration syncer, discoverer, escalator, history poller, history syncer, housekeeper, http poller, icmp pinger, ipmi manager, ipmi poller, java poller, lld manager, lld worker, odbc poller, poller, preprocessing manager, preprocessing worker, proxy poller, self-monitoring, snmp trapper, task manager, timer, trapper, unreachable poller, vmware collector

Supported types of proxy processes:
availability manager, configuration syncer, data sender, discoverer, heartbeat sender, history syncer, housekeeper, http poller, icmp pinger, ipmi manager, ipmi poller, java poller, odbs poller, poller, preprocessing manager, preprocessing worker, self-monitoring, snmp trapper, task manager, trapper, unreachable poller, vmware collector

Valid modes are:
avg - average value for all processes of a given type (default)
count - returns number of forks for a given process type, <state> should not be specified
max - maximum value
min - minimum value
<process number> - process number (between 1 and the number of pre-forked instances). For example, if 4 trappers are running, the value is between 1 and 4.

Valid states are:
busy - process is in busy state, for example, processing request (default).
idle - process is in idle state doing nothing.

Examples:
=> zabbix[process,poller,avg,busy] → average time of poller processes spent doing something during the last minute
=> zabbix[process,"icmp pinger",max,busy] → maximum time spent doing something by any ICMP pinger process during the last minute
=> zabbix[process,"history syncer",2,busy] → time spent doing something by history syncer number 2 during the last minute
=> zabbix[process,trapper,count] → amount of currently running trapper processes
zabbix[proxy,<name>,<param>]
Information about Zabbix proxy. Integer name: proxy name

Valid values for param are:
lastaccess - timestamp of last heart beat message received from proxy
delay - how long collected values are unsent, calculated as "proxy delay" (difference between the current proxy time and the timestamp of the oldest unsent value on proxy) + ("current server time" - "proxy lastaccess")

Example:
=> zabbix[proxy,"Germany",lastaccess]

fuzzytime() function can be used to check availability of proxies.
This item is always processed by Zabbix server regardless of host location (on server or proxy).
zabbix[proxy_history]
Number of values in the proxy history table waiting to be sent to the server. Integer (not supported on server)
zabbix[queue,<from>,<to>]
Number of monitored items in the queue which are delayed at least by <from> seconds but less than by <to> seconds. Integer from - default: 6 seconds
to - default: infinity
Time-unit symbols (s,m,h,d,w) are supported for these parameters.
zabbix[rcache,<cache>,<mode>]
Availability statistics of Zabbix configuration cache. Integer (for size); float (for percentage). cache: buffer

Valid modes are:
total - total size of buffer
free - size of free buffer
pfree - percentage of free buffer
used - size of used buffer
pused - percentage of used buffer

pused mode is supported since Zabbix 4.0.0.
zabbix[requiredperformance]
Required performance of Zabbix server or Zabbix proxy, in new values per second expected. Float Approximately correlates with "Required server performance, new values per second" in Reports → System information.
zabbix[stats,<ip>,<port>]
Remote Zabbix server or proxy internal metrics. JSON object. ip - IP/DNS/network mask list of servers/proxies to be remotely queried (default is 127.0.0.1)
port - port of server/proxy to be remotely queried (default is 10051)

Note that the stats request will only be accepted from the addresses listed in the 'StatsAllowedIP' server/proxy parameter on the target instance.

A selected set of internal metrics is returned by this item. For details, see Remote monitoring of Zabbix stats.

Supported since 4.2.0.
zabbix[stats,<ip>,<port>,queue,<from>,<to>]
Remote Zabbix server or proxy internal queue metrics (see zabbix[queue,<from>,<to>]). JSON object. ip - IP/DNS/network mask list of servers/proxies to be remotely queried (default is 127.0.0.1)
port - port of server/proxy to be remotely queried (default is 10051)
from - delayed by at least (default is 6 seconds)
to - delayed by at most (default is infinity)

Note that the stats request will only be accepted from the addresses listed in the 'StatsAllowedIP' server/proxy parameter on the target instance.

Supported since 4.2.0.
zabbix[tcache,cache,<parameter>]
Effectiveness statistics of the Zabbix trend function cache. Integer (for size); float (for percentage). Valid parameters are:
all - total cache requests (default)
hits - cache hits
phits - percentage of cache hits
misses - cache misses
pmisses - percentage of cache misses
items - the number of cached items
requests - the number of cached requests
pitems - percentage of cached items from cached items + requests. Low percentage most likely means that the cache size can be reduced.

Supported since 5.4.0.

(not supported on proxy)
zabbix[triggers]
Number of enabled triggers in Zabbix database, with all items enabled on enabled hosts. Integer (not supported on proxy)
zabbix[uptime]
Uptime of Zabbix server or Zabbix proxy process in seconds. Integer
zabbix[vcache,buffer,<mode>]
Availability statistics of Zabbix value cache. Integer (for size); float (for percentage). Valid modes are:
total - total size of buffer
free - size of free buffer
pfree - percentage of free buffer
used - size of used buffer
pused - percentage of used buffer

(not supported on proxy)
zabbix[vcache,cache,<parameter>]
Effectiveness statistics of Zabbix value cache. Integer

With the mode parameter:
0 - normal mode,
1 - low memory mode
Valid parameter values are:
requests - total number of requests
hits - number of cache hits (history values taken from the cache)
misses - number of cache misses (history values taken from the database)
mode - value cache operating mode

This item is supported since Zabbix 2.2.0 and the mode parameter since Zabbix 3.0.0.
(not supported on proxy)

Once the low memory mode has been switched on, the value cache will remain in this state for 24 hours, even if the problem that triggered this mode is resolved sooner.

You may use this key with the Change per second preprocessing step in order to get values per second statistics.
zabbix[version]
Version of Zabbix server or proxy. String This item is supported since Zabbix 5.0.0.

Example of return value: 5.0.0beta1
zabbix[vmware,buffer,<mode>]
Availability statistics of Zabbix vmware cache. Integer (for size); float (for percentage). Valid modes are:
total - total size of buffer
free - size of free buffer
pfree - percentage of free buffer
used - size of used buffer
pused - percentage of used buffer
zabbix[wcache,<cache>,<mode>]
Statistics and availability of Zabbix write cache. Specifying <cache> is mandatory.
Cache Mode
values all
(default)
Total number of values processed by Zabbix server or Zabbix proxy, except unsupported items. Integer Counter.
You may use this key with the Change per second preprocessing step in order to get values per second statistics.
float Number of processed float values. Integer Counter.
uint Number of processed unsigned integer values. Integer Counter.
str Number of processed character/string values. Integer Counter.
log Number of processed log values. Integer Counter.
text Number of processed text values. Integer Counter.
not supported Number of times item processing resulted in item becoming unsupported or keeping that state. Integer Counter.
history pfree
(default)
Percentage of free history buffer. Float History cache is used to store item values. A low number indicates performance problems on the database side.
free Size of free history buffer. Integer
total Total size of history buffer. Integer
used Size of used history buffer. Integer
pused Percentage of used history buffer. Float pused mode is supported since Zabbix 4.0.0.
index pfree
(default)
Percentage of free history index buffer. Float History index cache is used to index values stored in history cache.
Index cache is supported since Zabbix 3.0.0.
free Size of free history index history buffer. Integer
total Total size of history index history buffer. Integer
used Size of used history index history buffer. Integer
pused Percentage of used history index buffer. Float pused mode is supported since Zabbix 4.0.0.
trend pfree
(default)
Percentage of free trend cache. Float Trend cache stores aggregate for the current hour for all items that receive data.
(not supported on proxy)
free Size of free trend buffer. Integer (not supported on proxy)
total Total size of trend buffer. Integer (not supported on proxy)
used Size of used trend buffer. Integer (not supported on proxy)
pused Percentage of used trend buffer. Float (not supported on proxy)

pused mode is supported since Zabbix 4.0.0.