Setting Scaling Parameters for a Single Software Event Broker

To increase the the scaling parameters for a software event broker with Solace CLI, perform the following steps:

Step 1: Review the System Resource Requirements
Step 2: Increase the Value of the Scaling Parameter(s)

This procedure changes system-wide scaling parameters. Upon completion, you may need to modify other parameters for individual Message VPNs. For example, you may need to modify the maximum number of client connections permitted for a specific Message VPN (Configuring Maximum Connections) or for a specific client profile (see Configuring Max Connections Per Username). For more information, see Configuring Message VPNs.

System scaling parameters can only be increased.

This procedure is service affecting. To change system scaling parameters other than the Kafka scaling parameters, you must shut down the message backbone and message spool.

Step 1: Review the System Resource Requirements

Before changing scaling parameters, review the system resources that are required and ensure that your system is adequately provisioned for the new values you plan to set. When you set the maximum connections for containers, you may also need to set some docker create options in accordance with the new value. For details, see System Resource Requirements and Using System Scaling Parameters.

Step 2: Increase the Value of the Scaling Parameter(s)

In the Solace CLI, enter the show system command to review the current scaling values:

ip-132-42-25-151> show system

System Uptime: 0d 5h 21m 11s
Last Restart Reason: User request

Scaling:
   Max Bridges: 25
   Max Connections: 100
   Max Queue Messages: 100M
   Max Kafka Bridges: 0
   Max Kafka Broker Connections: 0

Topic Routing:
   Subscription Exceptions: Enabled
   Subscription Exceptions Defer: Enabled

Shut down the msg-backbone service and message-spool.

If you are increasing the Kafka scaling parameters (Kafka bridges or Kafka broker connections) you do not need to shut down the msg-backbone or message-spool.

ip-132-42-25-151> enable
ip-132-42-25-151# configure
ip-132-42-25-151(configure)# service msg-backbone shutdown
All clients will be disconnected.
Do you want to continue (y/n)? y
ip-132-42-25-151(configure)# hardware message-spool shutdown
All message spooling will be stopped.
Do you want to continue (y/n)? y

Increase the required scaling parameter value.
You can increase the values of the following system scaling parameters:
- maximum number of client connections (using the max-connections <connection-limit> command)
- maximum number of queue messages (using the max-queue-messages <max-messages-in-millions> command)
- maximum number of VPN bridges (using the max-bridges <max-bridges> command)
- maximum number of Kafka bridges (using the max-kafka-bridges <max-kafka-bridges> command)
- maximum number of Kafka broker connections (using the max-kafka-broker-connections <max-kafka-broker-connections> command)
For example, Step 1 shows that the initial value of the client connection limit is 100. To increase the connection limit to 1,000, enter the following commands:
```
ip-132-42-25-151(configure)# system
ip-132-42-25-151(configure/system)# scaling
ip-132-42-25-151(configure/system/scaling)# max-connections 1000
This command causes a reload of the system.
Do you want to continue (y/n)? y

Moving ADB messages to disk  : 100%
Backing up ADB config to disk: 100%

Performing database consolidation
```

Changing the value of system scaling parameters causes the system to reload, stopping the container. In machine images, the container automatically restarts. For container images, you may need to manually restart the container, depending on the restart policy of your container runtime.

Restart the container if required, then enter the CLI again and confirm the new parameter has been applied. In this example, the maximum number of client connections has been increased to 1,000.

ip-132-42-25-151> show system

System Uptime: 0d 5h 27m 43s
Last Restart Reason: User request

Scaling:
   Max Bridges: 25
   Max Connections: 1000
   Max Queue Messages: 100M
   Max Kafka Bridges: 0
   Max Kafka Broker Connections: 0

Topic Routing:
   Subscription Exceptions: Enabled
   Subscription Exceptions Defer: Enabled

Optionally, repeat the preceding two steps to increase another scaling parameter.
To resume messaging you must restart the msg-backbone service and message-spool.
If you are increasing the Kafka scaling parameters (Kafka bridges or Kafka broker connections) you do not need to restart the msg-backbone or message-spool.
```
ip-132-42-25-151> enable
ip-132-42-25-151# config
ip-132-42-25-151(configure)# no hardware message-spool shutdown
ip-132-42-25-151(configure)# no service msg-backbone shutdown
```

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