Host Throttling Performance Counters

Active instance count

Number of service instances active in memory. For the orchestration engine, a service instance refers to each running instance of an orchestration schedule. For the End Point Manager, a service instance may either correspond to a single stateless message, or to a collection of stateful messages.

Note

Stateful instances are those that maintain certain state information about the messages associated with the instance. Messages belonging to a stateful instance are co-related in some form or the other. For example an MSMQT message stream that maintains information about the sender and the message sequence, or an ordered send port that maintains information about the ordering are considered stateful instances. Most messaging scenarios involve stateless instances where messages are processed completely independent of each other. Each such stateless instance corresponds to a single message within the EPM.

Database session

Number of concurrent MessageBox database connections being used.

Database session threshold

The current threshold for concurrent database sessions. This is initially set to the value specified for Database connections per CPU on the Throttling Thresholds dialog available from the Advanced page of the Host Properties dialog box. This value is auto-tuned based on the database session usage of the process. If the number of concurrent database sessions exceeds this threshold at any time, host throttling is implemented.

Database size

Number of messages in the database queues that this process has published. This value is measured by the number of items in the queue tables for all hosts and the number of items in the spool and tracking tables. If a process is publishing to multiple queues, this counter reflects the weighted average of all the queues.

Note

If the host is restarted, statistics held in memory are lost. Since there is some overhead involved, BizTalk Server will resume gathering statistics only when there are at least 100 publishes with 5% of the total publishes within the restarted host process.

High database session

• 0: Normal
  
  
• 1: Database session count exceeds threshold
  
  

High database size

• 0: Normal
  
  
• 1: Database size has grown beyond threshold
  
  
  Note

  This counter will be set to a value of one if either of the conditions listed for the Message count in database threshold occurs. This threshold is documented in the topic How to Modify the Default Host Throttling Settings.

High in-process message count

• 0: Normal
  
  
• 1: In-process message count exceeds limit
  
  

High message delivery rate

• 0: Normal
  
  
• 1: Message delivery rate exceeds the message processing Rate
  
  

High message publishing rate

• 0: Normal
  
  
• 1: Publishing request rate exceeds completion rate
  
  

High process memory

• 0: Normal
  
  
• 1: Process memory exceeds threshold
  
  

High system memory

• 0: Normal
  
  
• 1: System memory exceeds threshold
  
  

High thread count

• 0: Normal
  
  
• 1: Thread count exceeds threshold
  
  

In-process message count

Number of in-memory messages delivered to the XLANG engine or the outbound messaging engine that are not yet processed.

In-process message count threshold

The current threshold for in-process message count.

Message delivery delay (ms)

The current delay in ms imposed on each message delivery batch (applicable if the message delivery is being throttled).

Message delivery incoming rate

Number of messages per second that are being delivered to the Orchestration engine or the Messaging engine in the given sample interval.

Message delivery outgoing rate

Number of messages per second that are being processed by the Orchestration engine or the Messaging engine in the given sample interval.

Message delivery throttling state

A flag indicating whether the system is throttling message delivery (affecting XLANG message processing and outbound transports).

• 0: Not throttling
  
  
• 1: Throttling due to imbalanced message delivery rate (input rate exceeds output rate)
  
  
• 3: Throttling due to high in-process message count
  
  
• 4: Throttling due to process memory pressure
  
  
• 5: Throttling due to system memory pressure
  
  
• 9: Throttling due to high thread count
  
  
• 10: Throttling due to user override on delivery
  
  

Message delivery throttling state duration

Seconds since the system entered this state. If the host is throttling, how long it has been throttling; if it is not throttling, how long since throttling was applied.

Message delivery throttling user override

This counter reflects the user override that is monitored by the engine and interpreted as follows:

• 0: No override
  
  
• 1: Always throttle message delivery
  
  
• 2: Do not throttle message delivery
  
  

Note

This override is configured by creating the REG_DWORD registry value ThrottlingDeliveryOverride at the following location in the registry: HKLM\System\CurrentControlSet\Services\BTSSvc$<HostName>

Message publishing delay (ms)

The current delay in ms imposed on each message publishing batch (applicable if the message publishing is being throttled and if the batch is not exempted from throttling).

Message publishing incoming rate

Number of messages per second that are being sent to the database for publishing in the given sample interval.

Message publishing outgoing rate

Number of messages per second that are actually published in the database in the given sample interval.

Message publishing throttling state

A flag indicating whether the system is throttling message publishing (affecting XLANG message processing and inbound transports).

• 0: Not throttling
  
  
• 2: Throttling due to imbalanced message publishing rate (input rate exceeds output rate)
  
  
• 4: Throttling due to process memory pressure
  
  
• 5: Throttling due to system memory pressure
  
  
• 6: Throttling due to database growth
  
  
• 8: Throttling due to high session count
  
  
• 9: Throttling due to high thread count
  
  
• 11: Throttling due to user override on publishing
  
  

Message publishing throttling state duration

Seconds since the system entered this state. If the host is throttling, how long it has been throttling; if it is not throttling, how long since throttling was applied.

Message publishing throttling user override

This counter reflects the user override that is monitored by the engine and interpreted as follows:

• 0: No override
  
  
• 1: Always throttle message publishing
  
  
• 2: Do not throttle message publishing
  
  

Note

This override is configured by creating the REG_DWORD registry value ThrottlingPublishOverride at the following location in the registry: HKLM\System\CurrentControlSet\Services\BTSSvc$<HostName>

Physical memory usage (MB)

The amount of physical memory in MB being used on the machine by all processes.

Process memory usage (MB)

The process memory consumption in MB. This is the maximum of the process’s working set size and the total space allocated for the page file for the process.

Process memory usage threshold (MB)

The current threshold for process memory consumption in MB. This is initially set to the value specified for Process memory usage on the Throttling Thresholds dialog available from the Advanced page of the Host Properties dialog box. If a percentage value is specified, it is computed based on the available memory to commit

Service class ID

The decimal value of the initial part of the service class GUID that this performance counter instance corresponds to. A process may host more than one service class and the message agent performance counters show the data for the most active service class.

Thread count

Number of threads being used within the process.

Thread count threshold

The current threshold for the number of threads in the process. This is initially set to the value specified for Threads per CPU on the Throttling Thresholds dialog available from the Advanced page of the Host Properties dialog box. This value is auto-tuned depending on the thread requirements of the current process. If the number of threads in the process exceeds this threshold value at any point in time, host throttling is implemented.

Total batches committed

Number of database batches that the service class has committed.

Total messages delivered

Number of outbound messages delivered to the Orchestration engine or the End Point Manager (EPM).

Total messages published

Number of messages published.