SNMP support for admin partitions

A partitioned NetScaler appliance uses SNMP infrastructure for partition rate limiting and for monitoring partition resource utilization details.

SNMP traps for admin partition rate limiting

On a partitioned NetScaler appliance, a PARTITION-RATE-LIMIT alarm can generate nine SNMP traps for notifying a partition resource (such as bandwidth, connection, or memory) has reached its limit or returned to normal.

The following nine SNMP traps are generated when:

• partitionCONNThresholdReached. The number of active connections for a partition exceeds its high threshold percentage.
• partitionCONNThresholdNormal. The number of active connections is less than or equal to the normal threshold percentage.
• partitionBWThresholdReached. The partition’s bandwidth usage reaches its high threshold percentage.
• partitionMEMThresholdReached. The current memory usage of the partition exceeds its high threshold percentage.
• partitionMEMThresholdNormal. The current memory usage of the partition becomes less than or equal to the normal threshold percentage.
• partitionMEMLimitExceeded. The current memory usage of the partition exceeds its memory limit percentage.
• partitionCONNLimitExceeded. The number of active connections for a partition exceeds its configured limit and new connections are being dropped.
• partitionCONNLimitNormal. The number of active connections for a partition goes below its configured limit and the partition can now accept a new connection.
• partitionBWLimitExceeded. The current bandwidth usage for a partition has exceeded its configured limit.

The threshold values for the SNMP traps are non-configurable and are as follows are:

• High threshold = 80% (applicable for all partition rate limit traps)
• Low threshold = 60 % (applicable for all partition rate limit traps)
• Memory limit = 95% (applicable only for partition memory traps)

Configuring PARTITION-RATE-LIMIT alarm

To configure PARTITION-RATE-LIMIT alarm in a specific partition and enable generation of the SNMP trap messages.

1. Enable  PARTITION-RATE-LIMIT Alarm
2. Configure PARTITION-RATE-LIMIT Alarm
3. Configure  SNMP Trap Destination

To enable PARTITION-RATE-LIMIT alarm by using the NetScaler CLI

At the command prompt, type the following commands:

enable snmp alarm PARTITION-RATE-LIMIT

show snmp alarm PARTITION-RATE-LIMIT

To configure PARTITION-RATE-LIMIT Alarm by using the NetScaler CLI

At the command prompt, type the following command

set snmp alarm PARTITION-RATE-LIMIT [-state ( ENABLED | DISABLED )] [-severity <severity>] [-logging ( ENABLED | DISABLED )]

To configure SNMP trap destination by using the NetScaler CLI

At the command prompt, type the following command:

add snmp trap <trapClass> <trapDestination> [-version <version>] [-td <positive_integer>] [-destPort <port>] [-communityName <string>] [-srcIP <ip_addr|ipv6_addr>] [-severity <severity>] [-allPartitions ( ENABLED | DISABLED )]

To configure PARTITION-Rate-Limit alarm by using the NetScaler GUI

Navigate to System > SNMP > Alarms, select  PARTITION-RATE-LIMIT alarm and configure the alarm parameters.

To configure SNMP trap destination by using the NetScaler GUI

Navigate to System > SNMP > Trap, specify the IP address of the destination device.

SNMP monitoring for partition resource utilization

Using SNMP, you can monitor a partition’s resource (such as bandwidth, connection, and memory) utilization details at real time on a NetScaler appliance. This is done by sending a SNMP request (such as SNMP GET, SNMP GET BULK, SNMP GETNEXT, or SNMP WALK) from the SNMP Manager.

Note

In order to monitor partition resources, you must configure the SNMP community in the default partition. Wherein, the partitionTable is maintained in the default partition, and the SNMP communication is done through the NSIP address of the appliance.

Consider a scenario where a NetScaler administrator wants to know the bandwidth usage of partition P1 on the appliance. The SNMP Manager retrieves this information by sending an SNMP GET request on the corresponding OID (partitionCurrentBandwidth) to the NSIP address of the appliance. The SNMP agent on the default partition retrieves and sends the current bandwidth usage of P1 to the SNMP Manager through the NSIP address.

The following table lists the SNMP counters which are part of partitionTable and its description: