Solace MessageSpool Test

Guaranteed messages are spooled to an event broker through the use of spool files. These files are stored on a Message Spool and the size you choose should match the number of messages that may need to be stored. If the spool files of the target event broker are all in use, then, the event broker cannot receive any more messages until some spooled messages are acknowledged which in turn would free some space in the message spool. If an event broker reaches its maximum spool file usage, negative acknowledgments (that is, 'NACKs') are returned to all publishing clients. However, thresholds can be configured so that events are generated when the usage of the message spool files gets too high.

Message spools can be created either with default sizes defined by service class type and connection size or is configurable. If the message spool is disabled or is inactive, then, the messages could not be spooled. Also, if the messages in the message spool are unacknowledged, then, the message spool will not deliver further messages to the clients until an acknowledgment is received. As a result, the size of the message spool will grow leading to sever disk space crunch. To ensure that the messages are delivered from the message spool at all times, it is essential to monitor the message spool of the target Solace PubSub+ Event Broker. The Solace Message Spool test helps administrators in this regard!

This test monitors the message spool of the target Solace PubSub+ Event broker and reports the configuration, operational and defragmentation status of the message spool. This test also helps administrators analyze the trend with which the messages are stored in the message spool, the disk space utilization based on the messages that were sent from the message spool, the utilization of the message spool files, etc. This way, administrators can get insights into the size of the message spool over a period of time and take informed decisions to increase the size of the message spool as and when necessary.

Target of the test : A Solace PubSub+ Event Broker

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the target Solace PubSub+ Event Broker being monitored

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The IP address of the target host for which this test is to be configured.

Port

Refers to the port at which the Solace PubSub+ Event Broker listens to.

UserName and Password

By default, the eG agent executes SEMP ( Solace Element Management Protocol) APIs on the target broker to collect the required metrics. For the eG agent to execute the SEMP APIs, a special user with read only privilege is required. Specify the credentials of such a user in the UserName and Password text boxes. To know how to create such a user, refer to Creating a New User for Monitoring Solace PubSub+ Event Broker.

Confirm Password

Confirm the Password by retyping it in the Confirm Password text box.

SSL

By default, this flag is set to No indicating that the Solace PubSub+ Event Broker is not SSL-enabled by default. Set this flag to Yes if the Solace PubSub+ Event Broker is SSL-enabled.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Config Status

Indicates the current configuration state of the message spool.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
Disabled 0
Enabled 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current configuration state of the message spool. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Operational status

Indicates the operational state of the message spool.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
AD-Active 1
Inactive 0

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the operational state of the message spool. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Datapath status

Indicates whether the message spool is enabled/disabled to use the storage volume in the target broker.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
Disabled 0
Enabled 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current datapath state of the message spool. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Guaranteed messaging support

Indicates whether guaranteed messaging is enabled or disabled.

 

Guaranteed Messaging must be enabled for clients.

By default, on Solace PubSub+ appliances, Guaranteed Messaging is not available for clients - a client profile that allows Guaranteed message publishing and/or receiving must be configured and assigned to a client username used by the clients. By default, on Solace PubSub+ software event brokers Guaranteed Messaging is enabled for clients.

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
Disabled 0
Enabled 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate whether guaranteed messaging is enabled or disabled. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Synchronization status

Indicates the synchronization state of the message spool i.e., whether/not the message spool of the target broker is in sync with the peer broker in a HA setup.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
Not-synchronized 0
Synchronized 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current synchronization state of the message spool. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Defragmentation status

Indicates the current defragmentation state of the message spool.

 

The spool files that a Solace PubSub+ event broker uses to store Guaranteed messages may become "fragmented" over time when consumers frequently go offline and do not reconnect. Fragmentation can occur because the small number of messages awaiting delivery to those offline consumers are maintained, which prevents the larger number of messages that have been consumed that are also on the spool file from being removed. This has the unwanted effect of consuming large quantities of disk space with messages that have already been delivered to consumers.

To remove the delivered messages from spool files and reclaim disk space, you can either manually trigger defragmentation or configure the event broker to automatically defragment the message spool.

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure values

 Numeric values
Not in idle 0
Idle 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current defragmentation state of the message spool. The graph of this measure however, is represented using the numeric equivalents only i.e., 0 or 1.

Number of deletes in progress

Indicates the number of messages that are currently deleted from the message spool.

Number

 

RFAD messages spooled

Indicates the number of ADB messages that were spooled in the message spool.

Number

If one or more of the clients are offline, or have fallen behind, the message is held in the ADB until it can be delivered. If there are too many messages to hold in the ADB’s memory, messages are written to the disk in large blocks.

Disk messages spooled

Indicates the number of disk messages that were spooled in the message spool.

Percent

 

Total messages spooled

Indicates the total number of messages that were spooled in the message spool.

Number

 

Spool files utilization

Indicates the percentage of spool files that were already utilized.

Percent

Guaranteed messages are spooled to an event broker through the use of spool files. These files are stored on a Message Spool and the size you choose should match the number of messages that may need to be stored. If the event broker’s spool files are all in use, it cannot receive any more messages until some spooled messages are acknowledged, which could free some space in the message spool.

If an event broker reaches its maximum spool file usage, negative acknowledgments (that is, 'NACKs') are returned to all publishing clients. However, thresholds can be configured so that events are generated when the usage of the message spool files gets too high.

Active diskpart utilization

Indicates the Current utilization of the disk partition expressed in percentage, on the active broker.

Percent

 

Transaction sessions count utilization

Indicates the percent utilization of total available transacted sessions.

Percent

 

Transaction sessions resource utilization

Indicates the percent utilization of total available transactions.

Percent

 

RFAD usage

Indicates the amount of space used by ADB messages that were spooled in the message spool.

MB

 

Disk usage

Indicates the amount of space used by the disk messages that were spooled in the message spool.

MB

 

Persist usage

Indicates the total amount of space utilized by the messages that were spooled in the message spool.

MB

 

Message count utilization

Indicates the percent utilization of total available message reference count.

Percent

 

Transacted session utilization

Indicates the percentage of transacted sessions.

Percent

Transacted Sessions enable client applications to group multiple message send and/or receive operations together in single, atomic units known as local transactions. Each transacted Session can support a single series of transactions.

Only Guaranteed messages (that is, messages with a Persistent or Non‑Persistent delivery mode) can be published or received through transactions; Direct messages cannot be used in transactions. Therefore, transacted Sessions can only be used with the Guaranteed Transport mode.

Delivered UNACK message utilization

Indicates the percent of messages delivered via message spool that are unacknowledged (UNACK).

Percent

A high value for this measure is a cause of concern.

If the messages are unacknowledged, then, the messages will not be delivered to the clients from the message spool unless an acknowledgment is received.

Defragmentation EST defragmentation

Indicates the estimated defragmentation of the spool files in the message spool expressed as percentage.

Percent

A high value for this measure indicates that a large number of consumers did not reconnect with the broker and therefore message delivery to those consumers are still pending from the spool files of the message spool.

Defragmentation EST recoverable

Indicates the amount of disk space that was recovered by removing the delivered messages from the message spool.

MB

A high value for this measure indicates that a large number of messages are pending to be delivered from the spool files of the message spool.

MessageSpool entity used by queue

Indicates the number of message spool entities used by the queues.

Number

 

MessageSpool entity used by dte

Indicates the number of message spool entities used by the Durable Topic Endpoints (DTE).

Number

A Topic Endpoint attracts messages published to a Topic that match the Topic subscription that is associated with the endpoint. An exclusive durable topic endpoint always delivers messages in the order they are received. For non-exclusive durable topic endpoints, multiple consumers can bind and each is serviced in round‑robin fashion.

Transacted session used

Indicates the current number of transacted sessions.

Number