[SERVER-5448] Add support for 'jsMode' during a sharded Map/Reduce Created: 29/Mar/12  Updated: 06/Dec/22  Resolved: 09/Mar/20

Status: Closed
Project: Core Server
Component/s: MapReduce
Affects Version/s: 2.1.0
Fix Version/s: None

Type: Improvement Priority: Major - P3
Reporter: Azat Khuzhin Assignee: Backlog - Query Team (Inactive)
Resolution: Won't Fix Votes: 6
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified
Environment:

2.1.1-pre-
Linux 2.6.32-5-amd64 #1 SMP Mon Oct 3 07:53:54 UTC 2011 x86_64 GNU/Linux


Issue Links:
Related
related to PHPLIB-309 mapReduce jsMode option should be uns... Closed
Assigned Teams:
Query
Participants:

 Description   

A mapReduce command issued against a sharded collection will fail with the message "unknown m/r field for sharding: jsMode". We should add support for using "jsMode" on sharded collections.

It does not appear that the jsMode option defaults to true, although it might have in some version before 3.4.

Original Description

Or maybe it not use jsMode in sharding environment by default?

If this is not true, it will be great if such feature will be added



 Comments   
Comment by Charlie Swanson [ 09/Mar/20 ]

During a recent project where we created a new implementation of mapReduce backed by the aggregation framework, we deprecated the 'jsMode' argument to mapReduce. This argument will be ignored starting in 4.4.0.

Comment by Charlie Swanson [ 10/Mar/17 ]

I've updated the ticket's summary and description to match my understanding of this request, please correct me if I've missed something.

Comment by Abhishek Kumar Singh [ 23/Aug/16 ]

Unaware of the fact that this feature has been removed from sharding , I moved my MR from standalone servers to sharded replica sets and now my programs running pretty slow.

Are there any plans of adding jsmode to sharding?

This will be a really great improvement on speed.

Comment by Mark Hall [ 31/Jul/14 ]

I'm using MR to compute profiling statistics for entire collections (mean, std. dev, categorical value frequencies etc.) and jsMode makes a huge difference (an order of magnitude faster). I would love to see this turned on for sharding.

Cheers,
Mark.

Comment by Antoine Girbal [ 04/Apr/12 ]

right, "jsMode" option is at root level and currently is rejected by mongos.
In theory it works fine with sharding, so it is just a matter of passing the flag through.

Comment by Eliot Horowitz (Inactive) [ 30/Mar/12 ]

No - it means the asignee needs to diagnose the issue, perhaps with more input from you.

Comment by Azat Khuzhin [ 29/Mar/12 ]

By changing status to "debugging with submitter" you mean than I must write what MR command to run ?

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