Page Comparison

There are lots of factors that determine the system health of a server. The hardware capabilities - CPU, memory or disk - is an important one, but also the server load - number of devices (Nodes to be polled, updated, audited, synchronised), number of products (NMIS, OAE, opCharts, opHA - each running different processes), number of concurrent users. 

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omkd_performance_logs => false

MongoDB memory usage

MongoDB, in its default configuration, will use will use the larger of either 256 MB or ½ of (ram – 1 GB) for its cache size.

MongoDB cache size can be changed by adding the cacheSizeGB argument to the /etc/mongod.conf configuration file, as shown below.

storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
  wiredTiger:
      engineConfig:
         cacheSizeGB: 1

Here is an interesting information regarding how MongoDB reserves memory for internal cache and WiredTiger, the underneath technology. Also some adjustment that can be done: https://dba.stackexchange.com/questions/148395/mongodb-using-too-much-memory

Server examples

Two servers are compared in this section.

• Master Primary only have one node, but more than 400 poller nodes. opHA process is what will require more CPU and memory usage. 
• Poller have more more than 500 nodes. nmis process will require more CPU and memory, for polling the information for all the nodes. 

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Daemons graphs:

omk:

mongo:

Stressed system 

Status
colour Green title Customer server UZH

System information:

nmis9d is crashing with no error messages. 

Some server info: 

• CentOS 7
• 463 Nodes
• Poller server
• High IO Wait 

Image Added

• increased open files to 100’000