The Talon Manual

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Comment: fix xml format

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Tip

You can set the environment property

Code Block
xml
xml
<env>
  <nv.optimizefor>latency</nv.optimizefor=latencyoptimizefor>
  <nv.consevercpu>true</nv.consevercpu=trueconsevercpu>

</env>


Listing of Threads

Talon Application Threads

ThreadNameCritical PathDescription
AEP Engine Input MultiplexerX-STEMux-<appName>-<instanceid>Yes

The engine thread that dequeues and dispatch application messages and events. This is the main application thread on which application events are dispatched. They are suffixed with a global counter to allow differentiating between stats emitted by multiple instances of the same application running in the same JVMAep.

The detached threads described outlined below can offload work from this thread which can improve throughput and latencies in your application.

(lightbulb) Note that when running in an XVM you will see AEP engine threads created for the XVM's admin application which is used to handle XVM admin requests.

X-EventMultiplexer-Wakeup-<appName>NoA timer thread use to wake up and dispatch events scheduled via the engine's input queue.
Detached Inbound Message LoggerX-ODS-StoreLog-<appName>.inNoWhen the application is configured with a detached inbound message logger, this thread offloads the work of writing to disk from the engine's input multiplexer which can serve as a buffer against disk I/O spikes.

As Inbound message loggers aren't used for HA purposes they are not on the critical path,

(lightbulb) If your application's inbound message load is not high, a detached inbound message logger may not be needed. The tleg3 transaction latency statistic covers inbound message logging. High values or spikes is an indicator that a detached inbound message logger can help
Detached Outbound Message LoggerX-ODS-StoreLog-<appName>.outNo 

When the application is configured with a detached outbound message logger, this thread offloads the work of writing to disk from the engine's input multiplexer which can serve as a buffer against disk I/O spikes.

 

(lightbulb) If your application's outbound message load is not high, a detached outbound message logger may not be needed. The tleg3 transaction latency statistic covers outbound message logging. High values or spikes is an indicator that a detached outbound message logger can help
Per Transaction Stats LoggerX-ODS-StoreLog-<appName>.txnstatsNo

When the application is configured with a detached per transaction stats logger, this thread offloads the work of writing to disk from the engine multiplexer which can serve as a buffer against disk I/O spikes.

(lightbulb) If your application's transaction load is not high, a detached per transaction stats logger message logger may not be needed. The cepilo (commit epilogue) transaction latency statistic covers per transaction stats logging costs. High values or spikes in cepilo is an indicator that a detached per transactions stats logger can help.

Bus Threads

Each bus configured for your application is managed by a Bus Manager internal to the AEP engine.

In addition to application configured buses, an engine creates several internal buses which are not on the critical processing path:

  • control-<uuid>: used for attaching internal AEP control events to transactions (for exampling fault tolerant timer related events).
  • client: used as a bus to which admin clients can connect to the application via an XVM rather than over a messaging bus.

Bus binding instances will generally create additional threads specific to the binding type.

Detached Bus Send ThreadX-AEP-BusManager-IO-<appName>.<busName>Yes

When the bus is configured for detached send, this thread offloads the work of serialization and writing of outbound messages from the engine's input multiplexer which serves as a buffer against spikes caused by message bus flow control.

(lightbulb) High values in the 'o2p, s, s2w, ws' message bus bindings stats are indicators that a detached bus sender can improve performance  

Bus Binding OpenerX-AEP-BusManager-BindingOpener-<appName>. <busName>No

Each bus configured for your application is managed by a Bus Manager internal to the AEP engine.

Handles establishment of the bus connects and reconnects.

Store Threads

Each store instance will minimally create a replication reader thread which handles reading from peers.

When a store is clustered

Store Reader ThreadX-ODS-StoreReplicatorLinkReader-<storeName>-<memberName>Yes

The IO thread for the store which is used to read replication traffic from cluster peers.

Detached Store PersisterX-ODS-StoreLog-<storeName>-<instanceid>No

When the store is configured for detached persistence, this thread offloads the work of writing recovery data to disk from the engine's input multiplexer which can serve as a buffer against disk I/O spikes.

(lightbulb) High values in the 'pers' (Persistencepersistence) store binding stats is an indicator that a detached store sender can improve performance.

Detached ICR SenderX-ODS-Store-ICR-Sender-<storeName>-<instanceid>NoWhen the store is configured for detached inter-cluster replication, this thread offloads the work of writing recovery data to the receiver from the engine's input multiplexer which can serve as a buffer against disk I/O spikes.

(lightbulb) High values in the 'icr' (inter-cluster replication) store binding stats is an indicator that a detached store sender can improve performance.
Detached Store Send ThreadX-ODS-StoreReplicatorSender-<storeName>-<memberName>Yes

When the store is configured for detached send, this thread offloads the work of writing recovery data to the network for backup instances from the engine's input multiplexer which can serve as a buffer against network I/O spikes.

(lightbulb) High values in the 's2w' (Serialize To Wireserialize to wire) store binding stats is an indicator that a detached store sender can improve performance.

Detached Store Dispatch ThreadX-ODS-StoreReplicatorDispatcher-<storeName>-<memberName>Yes

When the store is configured for detached dispatch, this thread allows the store reader thread to offload work of dispatching deserialized replication traffic to the engine for processing this is useful in cases where the cost of deserializing replication traffic is high.

(lightbulb) A high value for the store binding deserialize stat ('d'), can indicate that setting this property could improve throughput or latency.

Store Acceptor ThreadX-ODS-StoreLinkAcceptor-<instanceid>NoEach store configured for clustering will create a thread that will listen for connection requests from other store members. Once the connection is established it is handed off to the store reader thread for processing.
Miscellaneous 
Stats Printer ThreadsX-Stats-Printer [<statName>-<instanceid>.stats]NoSeveral components can be configured to trace stats (independently) from XVM collected stats. When such stats threads are enabled a thread is created to periodically print stats. This is typically useful if an app is run outside of an XVM.
SchedulerX-Scheduler-<instance-count> NoA timer thread used for scheduling events. An AepEngine uses this , for example, to perform period periodic engine health checks, for example.

Discovery Threads

ThreadThread NameCritical PathDescription
Discovery TimerX-EDP-TimerNo

Each discovery provider that is opened will create a timer thread that will periodically wake up to perform discovery broadcasts.

Each discovery provider typically will create additional threads specific to the discovery provider type. For example, when using an SMA-based discovery provider, message bus binding threads will be created.

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