Alex Pooley requested to merge 335733-faster-ci-runners-query into master Jul 19, 2021

What does this MR do?

Leverage the contacted_at indexes to improve the performance of the /api/:version/runners endpoint.

There's lots of specific info about the problem in the issue description.

This is only a one line MR. There's an existing spec for the modified .offline scope at https://gitlab.com/gitlab-org/gitlab/-/blob/master/spec/models/ci/runner_spec.rb#L371

Original query (NOT IN)

SELECT 
  "ci_runners".* 
FROM 
  (
    (
      SELECT 
        ci_runners.* 
      FROM 
        "ci_runner_projects" 
        INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_projects"."runner_id" 
      WHERE 
        "ci_runner_projects"."project_id" IN (
          SELECT 
            "projects"."id" 
          FROM 
            "projects" 
            INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id" 
          WHERE 
            "project_authorizations"."user_id" = 123456 
            AND (
              project_authorizations.access_level >= 40
            )
        )
    ) 
    UNION 
      (
        SELECT 
          ci_runners.* 
        FROM 
          "ci_runner_namespaces" 
          INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_namespaces"."runner_id" 
        WHERE 
          "ci_runner_namespaces"."namespace_id" IN (
            WITH RECURSIVE "base_and_descendants" AS (
              (
                SELECT 
                  "namespaces".* 
                FROM 
                  "namespaces" 
                  INNER JOIN "members" ON "namespaces"."id" = "members"."source_id" 
                WHERE 
                  "members"."type" = 'GroupMember' 
                  AND "members"."source_type" = 'Namespace' 
                  AND "namespaces"."type" = 'Group' 
                  AND "members"."user_id" = 123456
                  AND "members"."requested_at" IS NULL 
                  AND (access_level >= 10) 
                  AND "members"."access_level" = 50
              ) 
              UNION 
                (
                  SELECT 
                    "namespaces".* 
                  FROM 
                    "namespaces", 
                    "base_and_descendants" 
                  WHERE 
                    "namespaces"."type" = 'Group' 
                    AND "namespaces"."parent_id" = "base_and_descendants"."id"
                )
            ) 
            SELECT 
              id 
            FROM 
              "base_and_descendants" AS "namespaces"
          )
      )
  ) ci_runners 
WHERE 
  "ci_runners"."id" NOT IN (
    SELECT 
      "ci_runners"."id" 
    FROM 
      (
        (
          SELECT 
            ci_runners.* 
          FROM 
            "ci_runner_projects" 
            INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_projects"."runner_id" 
          WHERE 
            "ci_runner_projects"."project_id" IN (
              SELECT 
                "projects"."id" 
              FROM 
                "projects" 
                INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id" 
              WHERE 
                "project_authorizations"."user_id" = 123456
                AND (
                  project_authorizations.access_level >= 40
                )
            )
        ) 
        UNION 
          (
            SELECT 
              ci_runners.* 
            FROM 
              "ci_runner_namespaces" 
              INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_namespaces"."runner_id" 
            WHERE 
              "ci_runner_namespaces"."namespace_id" IN (
                WITH RECURSIVE "base_and_descendants" AS (
                  (
                    SELECT 
                      "namespaces".* 
                    FROM 
                      "namespaces" 
                      INNER JOIN "members" ON "namespaces"."id" = "members"."source_id" 
                    WHERE 
                      "members"."type" = 'GroupMember' 
                      AND "members"."source_type" = 'Namespace' 
                      AND "namespaces"."type" = 'Group' 
                      AND "members"."user_id" = 123456
                      AND "members"."requested_at" IS NULL 
                      AND (access_level >= 10) 
                      AND "members"."access_level" = 50
                  ) 
                  UNION 
                    (
                      SELECT 
                        "namespaces".* 
                      FROM 
                        "namespaces", 
                        "base_and_descendants" 
                      WHERE 
                        "namespaces"."type" = 'Group' 
                        AND "namespaces"."parent_id" = "base_and_descendants"."id"
                    )
                ) 
                SELECT 
                  id 
                FROM 
                  "base_and_descendants" AS "namespaces"
              )
          )
      ) ci_runners 
    WHERE 
      (
        contacted_at > '2021-07-17 03:20:43.164122'
      )
  ) 
ORDER BY 
  "ci_runners"."id" ASC 
LIMIT 
  20 OFFSET 0

Time: 1.226 min  
  - planning: 17.319 ms  
  - execution: 1.225 min  
    - I/O read: 1.098 min  
    - I/O write: 0.000 ms  
  
Shared buffers:  
  - hits: 4231419 (~32.30 GiB) from the buffer pool  
  - reads: 61716 (~482.20 MiB) from the OS file cache, including disk I/O  
  - dirtied: 3231 (~25.20 MiB)  
  - writes: 0

https://postgres.ai/console/gitlab/gitlab-production-tunnel-pg12/sessions/5211/commands/18399

New query (`contacted_at <= ?`)

SELECT 
  "ci_runners".* 
FROM 
  (
    (
      SELECT 
        ci_runners.* 
      FROM 
        "ci_runner_projects" 
        INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_projects"."runner_id" 
      WHERE 
        "ci_runner_projects"."project_id" IN (
          SELECT 
            "projects"."id" 
          FROM 
            "projects" 
            INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id" 
          WHERE 
            "project_authorizations"."user_id" = 123456 
            AND (
              project_authorizations.access_level >= 40
            )
        )
    ) 
    UNION 
      (
        SELECT 
          ci_runners.* 
        FROM 
          "ci_runner_namespaces" 
          INNER JOIN "ci_runners" ON "ci_runners"."id" = "ci_runner_namespaces"."runner_id" 
        WHERE 
          "ci_runner_namespaces"."namespace_id" IN (
            WITH RECURSIVE "base_and_descendants" AS (
              (
                SELECT 
                  "namespaces".* 
                FROM 
                  "namespaces" 
                  INNER JOIN "members" ON "namespaces"."id" = "members"."source_id" 
                WHERE 
                  "members"."type" = 'GroupMember' 
                  AND "members"."source_type" = 'Namespace' 
                  AND "namespaces"."type" = 'Group' 
                  AND "members"."user_id" = 123456 
                  AND "members"."requested_at" IS NULL 
                  AND (access_level >= 10) 
                  AND "members"."access_level" = 50
              ) 
              UNION 
                (
                  SELECT 
                    "namespaces".* 
                  FROM 
                    "namespaces", 
                    "base_and_descendants" 
                  WHERE 
                    "namespaces"."type" = 'Group' 
                    AND "namespaces"."parent_id" = "base_and_descendants"."id"
                )
            ) 
            SELECT 
              id 
            FROM 
              "base_and_descendants" AS "namespaces"
          )
      )
  ) ci_runners 
WHERE 
  (
    contacted_at <= '2021-07-17 03:20:43.164122'
  ) 
ORDER BY 
  "ci_runners"."id" ASC 
LIMIT 
  20 OFFSET 0

Time: 1.743 s  
  - planning: 3.731 ms  
  - execution: 1.740 s  
    - I/O read: 0.000 ms  
    - I/O write: 0.000 ms  
  
Shared buffers:  
  - hits: 2146584 (~16.40 GiB) from the buffer pool  
  - reads: 0 from the OS file cache, including disk I/O  
  - dirtied: 9 (~72.00 KiB)  
  - writes: 0

https://postgres.ai/console/gitlab/gitlab-production-tunnel-pg12/sessions/5211/commands/18411

Screenshots or Screencasts (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
I have added/updated documentation, or it's not needed. (Is documentation required?)
I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
I have self-reviewed this MR per code review guidelines.
This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
I have followed the style guides.
This change is backwards compatible across updates, or this does not apply.

Availability and Testing

I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
I have tested this MR in all supported browsers, or it's not needed.
I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

[-] Label as security and @ mention @gitlab-com/gl-security/appsec
[-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
[-] Security reports checked/validated by a reviewer from the AppSec team

Related to #335733 (closed)

Edited Jul 22, 2021 by Mayra Cabrera

Resolve "Slow ci runners query at /api/:version/runners"