[DOCS-16362] [SERVER] Investigate changes in SERVER-79724: Get rid of the AggregationTargeter::TargetingPolicy::kPassthrough and the entire “passthrough” code path in agg Created: 01/Sep/23  Updated: 08/Jan/24  Resolved: 06/Dec/23

Status: Closed
Project: Documentation
Component/s: manual, Server
Affects Version/s: None
Fix Version/s: 7.2 Targeted, Server_Docs_[20240108]

Type: Task Priority: Minor - P4
Reporter: Backlog - Core Eng Program Management Team Assignee: Caleb Thompson
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Documented
documents SERVER-79724 Get rid of the AggregationTargeter::T... Closed
Gantt Dependency
has to be done after SERVER-80145 Avoid explicit callers of ChunkManage... Closed
Participants:
Days since reply: 9 weeks, 2 days ago
Story Points: 3

 Description   
Original Downstream Change Summary

This patch changes shard targeting aggregation to no longer have a special case for unsharded collections (that is, aggregate command requests that target an unsharded collection use the same path as those which target a sharded collection). The effect of this is mostly invisible to the user, except for explain output, which in the case of an unsharded collection will put the output under the 'shards' field (previously, this was not done).

Another effect of this is that in $search against a sharded cluster, we will call 'planShardedSearch' for an unsharded collection.

Description of Linked Ticket

This code path should be unnecessary if the kAnyShard code path can handle all the cases with unsharded collections and route accordingly.

  • Eliminate LiteParsedPipeline::allowedToPassthroughFromMongos() and LiteParsedDocumentSource::allowedToPassthroughFromMongos()
  • Delete runPipelineOnPrimaryShard()


 Comments   
Comment by Caleb Thompson [ 04/Dec/23 ]

https://github.com/10gen/docs-mongodb-internal/pull/5493

Comment by Caleb Thompson [ 01/Dec/23 ]

Output when  calling 'explain' on an unsharded collection within a shared cluster:

 
"shards" : {
    "shard-rs0" : {
      "host" : "localhost:20001",
      "queryPlanner" : {
         "namespace" : "test.countscan",
         "indexFilterSet" : false,
         "parsedQuery" :

{           "foo" :                \{ "$gt" : 0 }

              },
         "queryHash" : "EB25B9AD",
         "planCacheKey" : "7C739F3B",
         "optimizedPipeline" : true,
         "maxIndexedOrSolutionsReached" : false,
         "maxIndexedAndSolutionsReached" : false,
         "maxScansToExplodeReached" : false,
         "winningPlan" : {
            "queryPlan" : {

Comment by Ashley Brown [ 03/Nov/23 ]

Blocked on SERVER-80145

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