Managing Instances In Nagios Log Server can be confusing if we don't know how to view, manage and troubleshoot them.
A clustered application, it consists of one or more instances of Nagios Log Server.
In this context, we shall look into how to view statistics and manage Nagios Log Server Instances.
Managing Instances In Nagios Log Server
An instance participates in the cluster and acts as a location for the log data to reside. The log data with the use of the Elasticsearch database spreads across the instances.
To manage Nagios Log Server Instances, we navigate to Admin > System > Instance Status.
1. Global Stats
This provides an overall summary of the instances in the cluster. We use this information to get an overview of the performance of the cluster.
We use this table to get a summary of each instance in the cluster. It gives us an overview of how each instance performs.
In the IP column, we click the IP address to bring up more information about that specific instance.
3. Instance Stats
This table will describe the statistics associated with this Nagios Log Server instance.
We use this information to know what the instance is capable of and the hardware they might need to introduce in a new instance.
4. Instance ID
We can find the Instance ID in the top right corner of the page. It is useful while we execute commands or when we review log files.
5. Instance Information
This table contains information about the underlying operating system parameters/capabilities.
i. IP address and Hostname
ii. Load over time
iii. Memory and Swap statistics
iv. CPU Statistics
v. CPU Physical properties
Here, we can see the statistics of the current process for this instance.
i. Open File Descriptors
ii. CPU statistics
iii. Memory status
7. File System
The file system used by the instance is found here.
i. File Data Path
ii. Mount and Device Paths
iii. Total and Free Space
iv. Disk Writes, Reads and Size
This table provides information about the indices this instance handles.
i. Number of Documents and any that have been deleted
ii. Store Size
iii. Totals of Indices, Deletions, Gets, Queries and Fetches
9. Java Virtual Machine (JVM)
This table has statistics about the JVM that runs Elasticsearch.
i. Heap and Non-Heap usage
ii. Uptime, Thread status
iii. GC Times and Counts
iv. Java version and JVM information
10. Thread Pools
A group of idle threads that stand ready until there is work.
i. Formatted by Queue/Peak/Active
ii. Each thread title indicates a section of the pool and the current threads we use
iii. Queued pools are waiting to be run
iv. Peak is the most threads the specific type of thread has ran at once
v. Active is any threads that are currently running
11. System Status
We can control the Elasticsearch and Logstash services on each Nagios Log Server instance via, Admin > System > System Status.
Under Subsystems, we use the Instance drop-down list to change the instance we want to control.
Then we use the Restart/Stop/Start commands to perform that action on the instance.
12. Advanced Management
For more detailed information about instances, we need to execute commands in a terminal session using a curl command.
To do so, we establish a terminal session to one of the Nagios Log Server instances and run:
$ curl -XGET 'http://localhost:9200/_cat/nodes/?v'
This will produce an output similar to the following:
[root@nls-c6x-x86 ~]# curl -XGET ‘http://localhost:9200/_cat/nodes/?v’
host ip heap.percent ram.percent load node.role master name
nls-c6x-x86.box293.local 10.25.5.85 50 70 0.08 d * 76e504ad-a6c9-4798
localhost 127.0.0.1 8 66 0.00 d m d20fa1fa-3a37-4a63
nls-r6x-x64.box293.local 10.25.5.98 24 86 0.00 d m edde1960-0cc2-4892