Sets a limit on the memory usage at the query level. Changing this attribute is effective immediately and may cause some queries to fail if the new value is smaller. If the user changes the setting to be unlimited, those 5 enqueued queries will remain enqueued until the running queries are done but new queries will start immediately.ĭefines the total memory that all queries running in parallel in a given queue can use per executor. For example, when the current limit is 5 and 10 long running queries have been submitted to the queue such that 5 of them are enqueued. Changing this attribute only affects new queries. Running queries continue using the previous setting until they complete.ĭefines how many queries are allowed to run in parallel. Changing this attribute only affects new or enqueued queries. Rule Configuration Options Categoryĭefines how much CPU time threads get respective to other threads. You can create custom rules, use the provided rule templates, or modify the provided rule templates.ĭremio implementation of using rules for queue assignment may change in the future. Rules are applied in order, the first rule that a query matches determines the action taken. Rules allow you to specify conditions that WLM uses to either assign a query to a queue or reject a query. For example, if you allow multiple concurrent jobs and if the total limit for each job is higher than the queue limit, then a job may fail if memory is consumed by other concurrent jobs. If you set up concurrency limits, ensure that you allocated job limits accordingly. If you delete a queue, Dremio prompts you to confirm your choice before deleting the queue.ĭremio provides the following generic queues as a starting point for customization: Rule Name If you edit an existing queue, all of the options are available for modification as when you add a new queue. If you add a new queue, you can customize the queue with the following configuration options. You can also add new queues, edit existing queues, or remove queues. The Rule's conditions that a job query matches, determines which queue the job query is sent to.ĭremio allows you to define job queues, to which queries can be assigned, based on defined rules. Rule4 indicates that any specified rule and/or all other queries can be rejected. The following diagram shows a basic WLM flow when a job query is submitted where Rule1 assigns job queries to Queue1, Rule2 to Queue2, Rule3 to Queue3, and so on. To access WLM, click the Settings (gear) icon near the bottom of the side navigation bar, and then click Queues.Ĭreating queues with different criteria depending on how you want to manage your jobs.Įstablish conditions that target specific queries.Īssign queries that fit the conditions to specific queues. If you have a heterogeneous environment (nodes in a Dremio cluster have different amounts of memory), you should plan for the lowest common denominator (lowest amount of memory associated with a node). That is, when each node in the Dremio cluster has the same amount of memory. Workload management works optimally in a homogeneous environment in terms of memory. Predictable and efficient utilization of cluster resources. Provides workload isolation and predictability for users and groups.Įase of configuration for SLA and workload management. In particular, WLM provides the following: This capability is particularly important in Dremio clusters that are deployed in multi-tenant environments with a variety of workloads ranging from exploratory queries to scheduled reporting queries. This is accomplished through defining a queue with specific characteristics (such as memory limits, CPU priority, and queueing and runtime timeouts) and then defining rules that specify which query is assigned to which queue. The Workload Management (WLM) feature provides the capability to manage cluster resources and workloads. Enterprise Edition only: For the Community Edition equivalent, see Queue Control.
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