Jaiganesh R S
03/13/2024, 12:19 PMScout
03/13/2024, 12:19 PMQueuedRunCoordinator
to manage the execution of runs. You can configure the dequeue_num_workers
setting to control how many runs are pulled from the run queue simultaneously. This can help you test how many jobs Dagster can handle at once.
- The relevant configuration snippet from the documentation is as follows:
yaml
run_coordinator:
module: dagster.core.run_coordinator
class: QueuedRunCoordinator
config:
dequeue_use_threads: true
dequeue_num_workers: 8
- Adjust the dequeue_num_workers
to the number of concurrent jobs you want to test.
2. Monitoring Memory Consumption:
- You can use monitoring tools that are compatible with your deployment environment to track memory usage. For instance, if you are running Dagster on Kubernetes, you can use metrics-server or a monitoring solution like Prometheus and Grafana to monitor memory consumption.
- Ensure that you have logging enabled for your jobs to capture any memory-related issues or errors that may occur during execution.
3. Limiting Concurrency:
- If you want to limit the overall concurrency to prevent overwhelming your system, you can use concurrency limits. This can also be a way to test how the system behaves under controlled load.
- The documentation provides guidance on limiting concurrency in data pipelines, which can be found [here](https://docs.dagster.io/guides/limiting-concurrency-in-data-pipelines#limiting-overall-concurrency-in-a-job).
4. Scaling Tests:
- Start with a small number of concurrent jobs and gradually increase the load while monitoring system performance and memory usage.
- Observe how the system behaves under different loads and identify any bottlenecks or performance degradation.
5. Reviewing System Logs and Metrics:
- After running your tests, review the logs and metrics collected to analyze the performance and memory consumption.
- Look for patterns or specific points where performance issues arise.
Remember to conduct these tests in a controlled environment that does not impact your production systems. Testing in an isolated environment will allow you to push the limits of the system without risking downtime or data loss.
Please note that the specifics of how to set up and run these tests will depend on your particular infrastructure and the complexity of your Dagster jobs. TScout
03/13/2024, 12:20 PMJaiganesh R S
03/13/2024, 12:23 PMScout
03/13/2024, 12:23 PMruns
query to fetch runs and filter them by status (e.g., IN_PROGRESS
). Then, for each run, you can query the steps and their status. 2. Use the Dagit Playground: Dagit, the web interface for Dagster, includes an interactive GraphQL playground where you can develop and test your queries. 3. Automate the Queries: Once you have the queries set up, you can automate them using a script or a tool that can execute GraphQL queries against the Dagster GraphQL endpoint. 4. Parse the Response: The response from the GraphQL API will need to be parsed to count the number of ops that are currently running. Here is an example of a GraphQL query that you might use to fetch the status of runs and their steps: graphql { runs(filter: {statuses: [STARTED]}) { results { runId status stepStats { stepKey status } } } }
This query fetches all runs that have a status of STARTED
and retrieves the runId
, overall status
of the run, and the status
of each step within the run. You would then need to iterate over the results and count the number of steps that have a status indicating they are currently running (e.g., IN_PROGRESS
). Please note that the exact field names and query structure may vary depending on the version of Dagster you are using, so you should refer to the [Dagster GraphQL API documentation](https://docs.dagster.io/concepts/dagit/graphql) for the most accurate and up-to-date information. If you prefer to query the database directly, you would need to understand the schema of the Dagster instance's underlying database. However, directly querying the database is not recommended because the schema could change between versions, and it is not part of the official API contract. Using the GraphQL API is the supported and recommended method for querying Dagster's state.Jaiganesh R S
03/13/2024, 12:30 PMScout
03/13/2024, 12:31 PMQueuedRunCoordinator
has a default limit of 10 concurrent runs, but you can adjust this limit to meet your needs. Here's the relevant part of the configuration for the `QueuedRunCoordinator`: yaml run_coordinator: module: dagster.core.run_coordinator class: QueuedRunCoordinator config: max_concurrent_runs: <desired_limit>
In the <desired_limit>
placeholder, you can specify the maximum number of concurrent runs you want to allow. If you want to remove the limit entirely, you can set this value to -1
, which means there is no limit on the number of concurrent runs. However, it's important to be cautious when setting this value to -1
, as it could potentially overwhelm your system's resources. Keep in mind that the appropriate limit for your use case will depend on various factors, including the complexity of your jobs, the resources of your execution environment, and the performance characteristics of the underlying infrastructure (e.g., database, compute resources). It's also worth noting that you can set concurrency limits at a more granular level using tags, which allows you to apply different limits to runs with specific tags. This can be useful if you have certain jobs that require stricter concurrency controls due to external dependencies or resource constraints. Here's an example of how you might configure tag-based concurrency limits: yaml run_coordinator: module: dagster.core.run_coordinator class: QueuedRunCoordinator config: tag_concurrency_limits: - key: "resource" value: "database" limit: 5 - key: "resource" value: "api" limit: 3
In this example, runs with the tag resource: database
are limited to 5 concurrent runs, while runs with the tag resource: api
are limited to 3 concurrent runs. When configuring concurrency limits, it's essential to balance the need for parallelism with the need to avoid overloading your systems. It's often a good idea to start with conservative limits and then adjust them based on observed performance and resource utilization.Jaiganesh R S
03/13/2024, 12:42 PMScout
03/13/2024, 12:42 PMmax_concurrent_runs
in your Dagster configuration based on your findings. Remember that you can always adjust this setting as you gather more data about your runs' performance. Remember that the maximum concurrency limit is not just about what the hardware can handle; it's also about maintaining system stability and performance. It's better to err on the side of caution and increase the limit gradually while monitoring the impact on system performance.Jaiganesh R S
03/13/2024, 12:43 PMJaiganesh R S
03/13/2024, 12:44 PMScout
03/13/2024, 12:44 PMScout
03/13/2024, 12:44 PM