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Zabbix Proxy: distributed NMS monitoring via embedded Linux (Ubuntu on BeagleBoard)

Arif — Thu, 19 Jul 2012 07:26:15 +0000

As already mentioned in previous post’s introduction, proof of concept on how Zabbix Proxy works under unreliable communication is what this next post about. The idea is to have these scenarios tested:

independent SNMP data polling by individual NMS proxy (embedded system)
intermittent connection between main/master NMS server with its proxy

Of course we’ll do them in implementation context of Zabbix Server as main/master NMS server and our BeagleBoard xM as its proxy.

Zabbix Proxy - distributed NMS over embedded Linux

In the technical details, I already followed pretty much the same steps showed in installation wiki (with the exception that I didn’t put the process into startup init.d script as I would start it manually as needed).

The first test is to make our Ubuntu ARM board accepts configuration done in Zabbix Server web-GUI, retrieves SNMP data to it, and sends collected data to server. Mode passive is chosen so that the server will be the one initiating contact with the board. After enabling a certain SNMP host, i.e. host-aaa, as monitored-by-proxy, the Zabbix Server log will show:

15677:20120601:022022.960 Sending configuration data to proxy 'beaglexm1'. Datalen 9205

Our board, ‘beaglexm1‘, will start to poll SNMP data from host-xxx to then store it in designated sqlite database.

975:20120531:212024.098 proxy #8 started [poller #5]
984:20120531:212024.128 proxy #17 started [discoverer #1]
968:20120531:212025.423 Received configuration data from server. Datalen 9205
971:20120531:212030.388 Enabling SNMP host [host-aaa]

From time to time as configured, our board will also run housekeeping to keep our board database file in small size.

1081:20120531:224513.922 Executing housekeeper
1081:20120531:224514.505 Deleted 4885 records from history [0.453765 seconds]

Under normal connection, in main Zabbix Server we’ll start seeing the collected data from host-aaa the same way as when the SNMP data is polled by the server directly. To emulate disruption to the connectivity, I choose to use simple iptables drop packet. This time the server will no longer seeing new data.

After the drop block is released, the server we’ll start seeing new data as well as data from the period of intermittent connection. It will take some time before all of that being sent to the server.

In general that proves it. I collected 44 OID values from the host-aaa every 30 seconds and in this case BeagleBoard utilization was very low as this wasn’t a stress test to see its performance.

Compile Zabbix Proxy in Ubuntu ARM (BeagleBoard)

Arif — Tue, 17 Jul 2012 08:28:57 +0000

I needed to tackle practical limitation of SNMP monitoring under unreliable communication, a serious consideration was made for Zabbix Proxy. It was an option said to be ready for embedded hardware. I already had BeagleBoard xM Rev C running Ubuntu 11.10 Oneiric and needed to proof that it would port functionally to this Linux ARM board. There existed zabbix-proxy-mysql in Oneiric repository, but sqlite seemed to be a better scale option for embedded deployment.

Zabbix Proxy Distributed NMS

An example set out for Zabbix Proxy on Debian appears to be pretty straightforward to follow. With the ARM board already installed with build-essential, snmp, and snmpd, the following needs to be added:

$ sudo apt-get install libsnmp-dev libcurl4-openssl-dev fping curl sqlite libsqlite3-dev ntpdate

then start the pre-compilation configure (in this case Zabbix 1.8.7 is used):

cd zabbix-1.8.7
./configure --enable-proxy --enable-agent --with-sqlite3 --with-net-snmp --with-libcurl

It will go smooth. However, during make there are complains about undefined references to ‘sqlite3_open‘, ‘sqlite3_close‘, etc.:

../../src/libs/zbxdb/libzbxdb.a(db.o): In function `zbx_db_connect':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:331: undefined reference to `sqlite3_open'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:343: undefined reference to `sqlite3_busy_timeout'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:334: undefined reference to `sqlite3_errmsg'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:335: undefined reference to `sqlite3_close'
../../src/libs/zbxdb/libzbxdb.a(db.o): In function `zbx_db_init':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:385: undefined reference to `sqlite3_open'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:387: undefined reference to `sqlite3_errmsg'
../../src/libs/zbxdb/libzbxdb.a(db.o): In function `zbx_db_close':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:446: undefined reference to `sqlite3_close'
../../src/libs/zbxdb/libzbxdb.a(db.o): In function `zbx_db_vexecute':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:827: undefined reference to `sqlite3_exec'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:852: undefined reference to `sqlite3_changes'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:833: undefined reference to `sqlite3_free'
../../src/libs/zbxdb/libzbxdb.a(db.o): In function `SQ_DBfree_result':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:1363: undefined reference to `sqlite3_free_table'
../../src/libs/zbxdb/libzbxdb.a(db.o): In function `zbx_db_vselect':
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:1121: undefined reference to `sqlite3_get_table'
/home/zabbix/zabbix-1.8.7/src/libs/zbxdb/db.c:1127: undefined reference to `sqlite3_free'

this is obviously from the database related code compilation. I run the gcc manually for the db.c file inside its directory by adding the flag ‘-lsqlite3‘ in the tail of ‘../../src/libs/zbxdb/libzbxdb.a‘ to make it work. Afterward by going to the initial directory first, running make again will then continue successfully.

$ cd src/zabbix_proxy
$ gcc -DZABBIX_DAEMON -g -O2     -L/usr/lib/arm-linux-gnueabi    -I/usr/local/include -I/usr/lib/perl/5.12/CORE -I. -I/usr/include      -I/usr/include -lsqlite3  -L/usr/lib/arm-linux-gnueabi -lcurl  -L/usr/lib -lnetsnmp -lcrypto  -L/usr/lib -lnetsnmp -lcrypto   -rdynamic    -o zabbix_proxy zabbix_proxy-servercomms.o zabbix_proxy-events.o zabbix_proxy-zlog.o zabbix_proxy-proxy.o heart/libzbxheart.a ../../src/zabbix_server/dbsyncer/libzbxdbsyncer.a ../../src/zabbix_server/discoverer/libzbxdiscoverer.a housekeeper/libzbxhousekeeper.a ../../src/zabbix_server/httppoller/libzbxhttppoller.a proxyconfig/libzbxproxyconfig.a ../../src/zabbix_server/pinger/libzbxpinger.a ../../src/zabbix_server/poller/libzbxpoller.a ../../src/zabbix_server/trapper/libzbxtrapper.a ../../src/zabbix_server/nodewatcher/libzbxnodewatcher.a datasender/libzbxdatasender.a ../../src/zabbix_server/selfmon/libzbxselfmon.a ../../src/libs/zbxsysinfo/libzbxserversysinfo.a ../../src/libs/zbxsysinfo/linux/libspecsysinfo.a ../../src/libs/zbxsysinfo/common/libcommonsysinfo.a ../../src/libs/zbxsysinfo/simple/libsimplesysinfo.a ../../src/libs/zbxlog/libzbxlog.a ../../src/libs/zbxdbcache/libzbxdbcache.a ../../src/libs/zbxmemory/libzbxmemory.a ../../src/libs/zbxalgo/libzbxalgo.a ../../src/libs/zbxnix/libzbxnix.a ../../src/libs/zbxsys/libzbxsys.a ../../src/libs/zbxconf/libzbxconf.a ../../src/libs/zbxcommon/libzbxcommon.a ../../src/libs/zbxcrypto/libzbxcrypto.a ../../src/libs/zbxcomms/libzbxcomms.a ../../src/libs/zbxcommshigh/libzbxcommshigh.a ../../src/libs/zbxjson/libzbxjson.a ../../src/libs/zbxexec/libzbxexec.a ../../src/libs/zbxself/libzbxself.a ../../src/libs/zbxserver/libzbxserver.a ../../src/libs/zbxicmpping/libzbxicmpping.a ../../src/libs/zbxdbhigh/libzbxdbhigh.a ../../src/libs/zbxdb/libzbxdb.a -lsqlite3 -lcurl  -lnetsnmp    -lm  -lresolv
$ cd ../../
$ make

Acknowledging Event: Zabbix Python API

Arif — Mon, 14 May 2012 02:40:43 +0000

Acknowledgement is one of the things that is provided by Zabbix API in its event section. We can make use of the methods get() and acknowledge() to automatically acknowledge an event. Digging through the attributes of those methods, the official doc doesn’t provide complete example to follow. Added with some luck, my search get me to have the following JSON RPC that works in Zabbix 1.8.7 using Gescheit API implementation written in Python.

When the goal is to acknowledge a specific event, the JSON call is however limited to some basic responses. It means that you can’t query a single RPC request for i.e. the following combination: list of acknowledged events with “problem” status and trigger ID 500 (500 is merely an example).

However, combination in a single request do exist i.e. I’ve tried: list of acknowledged events with “problem” status as the following GET request:

{
"params": {"acknowledged": [1], "value": [1]}, "jsonrpc": "2.0",
"method": "event.get",
"auth": "some-hash-authentication",
"id": some-RPC-sequence-integer
}

(Note: value=1 means status is “problem”)

For the basic example above, find the script in my fork of Gescheit API.

Back to our goal of acknowledging events, our API can make the following RPCs:

ack_list=zapi.event.get({"acknowledged":[1]})
problem_list=zapi.event.get({"value":[1]})
event_trigger_list=zapi.event.get({"triggerids":[trigger_id]})

Yes, they are three requests. We can then filter out a single event to be acknowledged by intersecting the three results. The first intersection is between event_trigger_list, problem_list, and ack_list as illustrated below:

Intersection of problem list, event list with specific trigger ID, and acknowledged event list

After we opt-out those intersections, we can then get the event with problem status and choose the latest event only to be acknowledged. Check the code on my github.