Generate Raptor transfer cache in parallel

[miklcct]

Summary

This makes the Raptor cache generating process run in parallel.

Our GB-wide deployment pre-caches 4 configurations on startup. Before applying this fix, it takes 16 minutes to cache 4 configurations for the whole GB on a 16-core machine:

Dec 09 17:54:06 lemon java[1497422]: 17:54:06.305 INFO [main]  (ConstructApplication.java:242) Creating initial raptor transfer cache progress tracking started.
Dec 09 17:58:31 lemon java[1497422]: 17:58:31.315 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, walk: WalkPreferences{reluctance: 1.68, boardCost: $300}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}}
Dec 09 17:58:31 lemon java[1497422]: 17:58:31.323 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 1 of 4 (25%)
Dec 09 18:02:42 lemon java[1497422]: 18:02:42.391 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, wheelchair, walk: WalkPreferences{reluctance: 1.68, boardCost: $300}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}, wheelchairPreferences: WheelchairPreferences{trip: AccessibilityPreferences{}, stop: AccessibilityPreferences{}, slopeExceededReluctance: 50.0, stairsReluctance: 25.0}}
Dec 09 18:02:42 lemon java[1497422]: 18:02:42.394 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 2 of 4 (50%)
Dec 09 18:06:41 lemon java[1497422]: 18:06:41.853 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, walk: WalkPreferences{reluctance: 1.0, boardCost: $0}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}}
Dec 09 18:06:41 lemon java[1497422]: 18:06:41.855 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 3 of 4 (75%)
Dec 09 18:10:50 lemon java[1497422]: 18:10:50.696 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, wheelchair, walk: WalkPreferences{reluctance: 1.0, boardCost: $0}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}, wheelchairPreferences: WheelchairPreferences{trip: AccessibilityPreferences{}, stop: AccessibilityPreferences{}, slopeExceededReluctance: 50.0, stairsReluctance: 25.0}}
Dec 09 18:10:50 lemon java[1497422]: 18:10:50.698 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 4 of 4 (100%)
Dec 09 18:10:50 lemon java[1497422]: 18:10:50.698 INFO [main]  (ConstructApplication.java:251) Creating initial raptor transfer cache progress tracking complete. 4 done in 16m44s (0 per second).

After applying this patch, it only takes 5 minutes:

Dec 09 18:46:09 lemon java[1500378]: 18:46:09.979 INFO [main]  (ConstructApplication.java:242) Creating initial raptor transfer cache progress tracking started.
Dec 09 18:47:31 lemon java[1500378]: 18:47:31.036 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, walk: WalkPreferences{reluctance: 1.68, boardCost: $300}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}}
Dec 09 18:47:31 lemon java[1500378]: 18:47:31.044 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 1 of 4 (25%)
Dec 09 18:48:46 lemon java[1500378]: 18:48:46.023 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, wheelchair, walk: WalkPreferences{reluctance: 1.68, boardCost: $300}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}, wheelchairPreferences: WheelchairPreferences{trip: AccessibilityPreferences{}, stop: AccessibilityPreferences{}, slopeExceededReluctance: 50.0, stairsReluctance: 25.0}}
Dec 09 18:48:46 lemon java[1500378]: 18:48:46.026 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 2 of 4 (50%)
Dec 09 18:50:02 lemon java[1500378]: 18:50:02.286 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, walk: WalkPreferences{reluctance: 1.0, boardCost: $0}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}}
Dec 09 18:50:02 lemon java[1500378]: 18:50:02.287 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 3 of 4 (75%)
Dec 09 18:51:18 lemon java[1500378]: 18:51:18.349 INFO [main]  (RaptorRequestTransferCache.java:44) Initializing cache with request: StreetRelevantOptions{transferMode: WALK, wheelchair, walk: WalkPreferences{reluctance: 1.0, boardCost: $0}, street: StreetPreferences{drivingDirection: LEFT, accessEgress: AccessEgressPreferences{maxDuration: DurationForStreetMode{default:2h}}}, wheelchairPreferences: WheelchairPreferences{trip: AccessibilityPreferences{}, stop: AccessibilityPreferences{}, slopeExceededReluctance: 50.0, stairsReluctance: 25.0}}
Dec 09 18:51:18 lemon java[1500378]: 18:51:18.352 INFO [main]  (ConstructApplication.java:248) Creating initial raptor transfer cache progress: 4 of 4 (100%)
Dec 09 18:51:18 lemon java[1500378]: 18:51:18.353 INFO [main]  (ConstructApplication.java:251) Creating initial raptor transfer cache progress tracking complete. 4 done in 5m8s (0 per second).

Also, the journey planning response time for a new configuration has been reduced correspondingly from more than 4 minutes to around 1.5 minutes.

Issue

#6312

Unit tests

None. This is a performance improvement only with no externally visible change.

Documentation

N/A

Changelog

Bumping the serialization version id

Not needed

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 69.81%. Comparing base (20696c1) to head (cded867).
Report is 84 commits behind head on dev-2.x.

Files with missing lines	Patch %	Lines
...thm/raptoradapter/transit/RaptorTransferIndex.java	85.71%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##             dev-2.x    #6326      +/-   ##
=============================================
+ Coverage      69.79%   69.81%   +0.01%     
- Complexity     17798    17827      +29     
=============================================
  Files           2019     2019              
  Lines          76126    76250     +124     
  Branches        7786     7803      +17     
=============================================
+ Hits           53132    53233     +101     
- Misses         20288    20302      +14     
- Partials        2706     2715       +9     

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[t2gran]

I think this is going to reduce the throughput slightly. The issue is that one request that require new transfers to be generated will steel processor time from other requests. I am not sure how the affect memory fetches, but It might have a negative effect on running trip searches - at least if a planning request is swapped out in favour of calculating transfers.

The threads also loose log-trace-parameters-propagation and graceful timeout handling.

The parrallel procecing at least need to be feature enabled using OTPFeature.ParallelRouting.isOn().

[optionsome]

There is also a possibility that these are only computed in parallel before start up but not after server is running. I don't know whether this code is used for both cases or not.

[miklcct]

There is also a possibility that these are only computed in parallel before start up but not after server is running. I don't know whether this code is used for both cases or not.

I specifically need it to compute in parallel in order to make our response time down from 4 minute to 1 minute.

[optionsome]

Only check the feature flag during run time, not during start-up.