Debug topology synchronization
StackState Self-hosted v5.1.x
Overview
This page explains several tools that can be used to troubleshoot a topology synchronization.
Topology synchronization process
A topology synchronized using StackState Agent follows the process described below:
StackState Agent:
Connects to a data source to collect data.
Connects to the StackState Receiver to push collected data to StackState (in JSON format).
StackState Receiver:
Extracts topology and telemetry payloads from the received JSON.
Puts messages on the Kafka bus.
Kafka:
Stores received data in topics.
Read the troubleshooting steps for Kafka.
Synchronization:
Reads data from a topic as it becomes available on the Kafka bus.
Processes retrieved data.
Troubleshooting steps
Confirm that a custom synchronization is running:
Use the
stacCLI to list all topology synchronization streams.The synchronization should be included in the list and have created components/relations.
If a custom synchronization isn't listed, you will need to recreate the synchronization.
If no components appear after making changes to a synchronization, or the data isn't as expected, follow the steps described in the sections below to check each step in the topology synchronization process.
If relations are missing from the topology, read the note on troubleshooting synchronization of relations.
StackState Agent
For integrations that run through StackState Agent, StackState Agent is a good place to start an investigation.
Check the StackState Agent log for hints that it has problems connecting to StackState.
The integration can be triggered manually using the
stackstate-agent check <check_name> -l debugcommand on your terminal. This command won't send any data to StackState. Instead, it will return the topology and telemetry collected to standard output along with any generated log messages.
StackState Receiver
The StackState Receiver receives JSON data from StackState Agent V3.
Check the StackState Receiver logs for JSON deserialization errors.
Kafka
Topology and telemetry are stored on Kafka on separate topics. The StackState topology synchronization reads data from a Kafka bus once it becomes available.
Use the stac CLI to list the topics on Kafka and check the messages on a topic:
List all topics present on Kafka:
stac topology list-topics. A topic should be present where the name has the formatsts_topo_<instance_type>_<instance url>where<instance_type>is the recognizable name of an integration and<instance_url>corresponds to the StackState Agent integration YAML (usually the URL of the data source).Check messages on a Kafka topic:
stac topic show <topic_name>. If there are recent messages on the Kafka bus, then the issue isn't in the data collection.
Synchronization
The StackState topology synchronization reads messages from a topic on the Kafka data bus. The Kafka topic used by a synchronization is defined in the Sts data source.
Check if the topic name defined in the Sts data source matches what is returned by the
stackstate-agent checkcommand. Note that topic names are case-sensitive.Check the error counter for the synchronization on the StackState UI page Settings > Topology Synchronization > Synchronizations. Increasing numbers tell you that there was an error while processing received data.
To troubleshoot processing errors, refer to the relevant StackState log files. The provided log messages will help you to resolve the issue. For details on working with the StackState log files on Kubernetes and Linux see the pages under Configure > Logging.
Check the
stackstate.logor, for Kubernetes, thestackstate-apipod.If there is an issue with the ID extractor, an exception will be logged here on each received topology element. No topology will be synchronized, however, the synchronization’s error counter will not increase.
Check the synchronization’s specific log file or, for Kubernetes, the
stackstate-syncpod for log messages that include the synchronization’s name.Issues with a mapping function defined for a synchronization mapping will be reported here. The type is also logged to help determine which mapping to look at. The synchronization’s error counter will increase.
Issues with templates are also logged here. The synchronization’s error counter will increase.
Relations
It's possible that a relation references a source or target component that doesn't exist. Components are always processed before relations. If a component referenced by a relation isn't present in the synchronization’s topology, the relation won't be created. When this happens, a warning is logged to the synchronization’s specific log file or the stackstate-sync pod. The component external ID and relation external ID are logged to help.
Synchronization logs
When StackState is deployed on Kubernetes, logs about synchronization can be found in the stackstate-sync pod and the stackstate-api pod. The name of the synchronization is shown in the log entries.
The
stackstate-syncpod has details of:Template/mapping function errors.
Component types that don't have a mapping.
Relations connected to a non-existing component.
Messages that have been discarded due to a slow synchronization.
The
stackstate-apipod has details of:ID extractor errors.
StackPacks.
When StackState is deployed on Linux, logs about synchronization are stored in the directory:
<my_install_location>/var/log/sync/
There are two log files for each synchronization:
exttopo.<DataSource_name>.loghas information about ID extraction and the building of an external topology. Here you will find details of:ID extractor errors.
Relations connected to a non-existing component.
Messages that have been discarded due to a slow synchronization.
sync.<Synchronization_name>.loghas information about mapping, templates and merging. Here you will find details of:Template/mapping function errors.
Component types that don't have a mapping.
Logs about StackPacks are stored in the directory:
<my_install_location>/var/log/stackpacks/
There is a log file for each StackPack. The name of the log file is set to the StackPack’s internal name. Information about the StackPack lifecycle can be found here.
Useful CLI commands
List all topology synchronization streams
Returns a list of all current topology synchronization streams.
# List streams
stac topology list
Node Id Identifier Status Created Components Deleted Components Created Relations Deleted Relations Errors
--------------- --------------------------------------------------------------------------------------- -------- -------------------- -------------------- ------------------- ------------------- --------
245676427469735 Running 0 0 0 0 0
154190823099122 urn:stackpack:stackstate-agent-v2:shared:sync:agent Running 761818 763870 1517959 1519490 0
144667609743389 urn:stackpack:stackstate:instance:44a9ce1e-413c-4c4c-819d-2095c1229dda:sync:stackstate Running 13599 5496 0 0 329⚠️ From StackState v5.0, the old sts CLI is called stac. The old CLI is now deprecated.
The new sts CLI replaces the stac CLI. It's advised to install the new sts CLI and upgrade any installed instance of the old sts CLI to stac. For details see:
Command not currently available in the new sts CLI. Use the stac CLI.
Show status of a stream
Shows the data of a specific topology synchronization stream, including detailed latency of the data being processed. The id might be either a node id or the identifier of a topology synchronization. The search gives priority to the node id.
# Show a topology synchronization status
stac topology show urn:stackpack:stackstate:instance:44a9ce1e-413c-4c4c-819d-2095c1229dda:sync:stackstate
Node Id Identifier Status Created Components Deleted Components Created Relations Deleted Relations Errors
--------------- --------------------------------------------------------------------------------------- -------- -------------------- -------------------- ------------------- ------------------- --------
144667609743389 urn:stackpack:stackstate:instance:44a9ce1e-413c-4c4c-819d-2095c1229dda:sync:stackstate Running 13599 5496 0 0 329
metric value between now and 500 seconds ago value between 500 and 1000 seconds ago value between 1000 and 1500 seconds ago
----------------- --------------------------------------- ---------------------------------------- -----------------------------------------
latency (Seconds) 35.754 --- ---⚠️ From StackState v5.0, the old sts CLI is called stac. The old CLI is now deprecated.
The new sts CLI replaces the stac CLI. It's advised to install the new sts CLI and upgrade any installed instance of the old sts CLI to stac. For details see:
Command not currently available in the new sts CLI. Use the stac CLI.
See also
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