Improve memory consumption of issuable APIs (!61561) · Merge requests · GitLab.org / GitLab

Heinrich Lee Yu requested to merge 211373-improve-issues-list-api-memory into master May 12, 2021

What does this MR do?

Sets replace_methods: false when batchloading issuable metadata. Explanation of this option is in: https://github.com/exAspArk/batch-loader#replacing-methods

For this particular case, the batch loader resolves Gitlab::IssuableMetadata::IssuableMeta objects which is a Struct. This results in __replace_with! being called on each of these.

[4] pry(main)> Gitlab::IssuableMetadata::IssuableMeta.new.methods.count
=> 198

This defines 198 methods per instance when we actually only call 5 of these methods. And we only call these methods only once so having them defined instead of relying on method_missing is not worth it. And for these API calls we'd have 20 to 100 instances depending on per_page values.

From local testing, disabling replace_methods even reduces cpu_s very slightly.

Sample logs before the change

{"time":"2021-05-12T06:22:48.629Z","severity":"INFO","duration_s":0.18625,"db_duration_s":0.0286,"view_duration_s":0.15765,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.115446,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.275191,"mem_objects":372737,"mem_bytes":21988696,"mem_mallocs":188096,"correlation_id":"01F5FKVZ04FVJNMSJE7BJA9T1V","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:22:49.445Z","severity":"INFO","duration_s":0.18799,"db_duration_s":0.02884,"view_duration_s":0.15915,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.119122,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.281203,"mem_objects":372763,"mem_bytes":21995864,"mem_mallocs":188105,"correlation_id":"01F5FKVZSF43EMPW5CMRZTAKZ8","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:22:50.309Z","severity":"INFO","duration_s":0.18767,"db_duration_s":0.02907,"view_duration_s":0.1586,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.132683,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.294494,"mem_objects":372770,"mem_bytes":22135288,"mem_mallocs":190615,"correlation_id":"01F5FKW0M21MJSPS2Z8V5V2MHQ","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:22:51.019Z","severity":"INFO","duration_s":0.19539,"db_duration_s":0.02928,"view_duration_s":0.16611,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.118343,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.288916,"mem_objects":372747,"mem_bytes":21995864,"mem_mallocs":188105,"correlation_id":"01F5FKW1ADQNCDZ2HZXSJHHMGZ","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:22:51.735Z","severity":"INFO","duration_s":0.19222,"db_duration_s":0.02829,"view_duration_s":0.16393,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.117654,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.284387,"mem_objects":372763,"mem_bytes":21995888,"mem_mallocs":188105,"correlation_id":"01F5FKW20X8G2W56DAFMZFVM95","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:22:52.442Z","severity":"INFO","duration_s":0.18587,"db_duration_s":0.02855,"view_duration_s":0.15732,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.125344,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.276808,"mem_objects":372772,"mem_bytes":21995864,"mem_mallocs":188105,"correlation_id":"01F5FKW2Q06GBBG0E8AP4HBKKV","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}

Sample logs after the change

{"time":"2021-05-12T06:27:37.031Z","severity":"INFO","duration_s":0.1684,"db_duration_s":0.02812,"view_duration_s":0.14028,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.129815,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.27261,"mem_objects":293662,"mem_bytes":13248280,"mem_mallocs":107112,"correlation_id":"01F5FM4RMTAXXC8WRHJ3B4V3WT","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:37.858Z","severity":"INFO","duration_s":0.18477,"db_duration_s":0.02964,"view_duration_s":0.15513,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.119745,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.277354,"mem_objects":293667,"mem_bytes":13306360,"mem_mallocs":107892,"correlation_id":"01F5FM4SEE9C9PGTCK3S94K3Y5","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:38.676Z","severity":"INFO","duration_s":0.16984,"db_duration_s":0.02886,"view_duration_s":0.14098,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.119228,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.262974,"mem_objects":293666,"mem_bytes":13159224,"mem_mallocs":105907,"correlation_id":"01F5FM4T8GZ47A58143SX0FYNP","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:39.560Z","severity":"INFO","duration_s":0.18291,"db_duration_s":0.02952,"view_duration_s":0.15339,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.124057,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.280885,"mem_objects":293670,"mem_bytes":13282696,"mem_mallocs":107512,"correlation_id":"01F5FM4V3HDVNK81YNAZNW4SZ9","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:40.364Z","severity":"INFO","duration_s":0.17219,"db_duration_s":0.02941,"view_duration_s":0.14278,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.135933,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.281485,"mem_objects":293664,"mem_bytes":13248488,"mem_mallocs":108172,"correlation_id":"01F5FM4VWMWVD7RK2CEZ01W87P","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:41.139Z","severity":"INFO","duration_s":0.1687,"db_duration_s":0.02784,"view_duration_s":0.14086,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.116833,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.260638,"mem_objects":293662,"mem_bytes":13157784,"mem_mallocs":105904,"correlation_id":"01F5FM4WNH48PEDAMG3R2Y2B6B","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}
{"time":"2021-05-12T06:27:43.367Z","severity":"INFO","duration_s":0.17228,"db_duration_s":0.02873,"view_duration_s":0.14355,"status":200,"method":"GET","path":"/api/v4/projects/1/issues","params":[],"host":"engwan-dev","remote_ip":"192.168.88.241","ua":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0","route":"/api/:version/projects/:id/issues","user_id":1,"username":"root","queue_duration_s":0.11832,"db_count":27,"db_write_count":0,"db_cached_count":5,"cpu_s":0.264453,"mem_objects":293662,"mem_bytes":13165016,"mem_mallocs":105907,"correlation_id":"01F5FM4YV1RDSR7F642RXH5ZPH","meta.user":"root","meta.project":"gitlab-org/gitlab-test","meta.root_namespace":"gitlab-org","meta.caller_id":"GET /api/:version/projects/:id/issues","meta.remote_ip":"172.18.0.1","meta.feature_category":"issue_tracking","meta.client_id":"user/1"}

From the logs we can see that mem_objects, mem_bytes, and mem_mallocs go down by a sizeable amount.

I am hoping this can help with #211373 (closed) because I see a lot of GC cycles during the performance test for this endpoint.

I'm struggling to find a lower hanging fruit to improve performance of this endpoint because it's already fast in staging (~300ms) but not in reference environments (~1s). https://staging.gitlab.com/api/v4/projects/gpt%2Flarge_projects%2Fgitlabhq1/issues is the URL being tested.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

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Related to #211373 (closed)

Edited May 12, 2021 by Heinrich Lee Yu

Improve memory consumption of issuable APIs