Details
Major - P3 Description
In a sharded cluster environment, getIndexes() reports indexes as defined on the database's Primary shard's primary node. It could be useful to have a convenient way of obtaining indexes on a per-shard (or even per-node given getIndexes on a primary reports indexes on that node) basis.
original
When creating an index on a shard that does not have the Primary role, mongoS does not find the index.
For example:
# Shard information
|
{ "_id" : "vinnie", "primary" : "shard02", "partitioned" : true, |
"version" : { "uuid" : UUID("2ff1e7eb-0a75-4bde-ac8f-bff4e93dfc4a"), "lastMod" : 1 } } |
{ "_id" : "vinnie", "primary" : "shard02", "partitioned" : true, |
"version" : { "uuid" : UUID("2ff1e7eb-0a75-4bde-ac8f-bff4e93dfc4a"), "lastMod" : 1 } } |
vinnie.companies
|
shard key: { "_id" : 1 } |
unique: false |
balancing: true |
chunks:
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shard01 7 |
shard02 8 |
shard03 7 |
Create the index on shard01:
shard01:PRIMARY> use vinnie;
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switched to db vinnie
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shard01:PRIMARY> db.companies.createIndex({firm: 1}){ "createdCollectionAutomatically" : false, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1, |
The result on mongoS:
mongos> db.companies.getIndexes()mongos> db.companies.getIndexes()
|
[ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "vinnie.companies" }] |
Now, if I create the index on the Primary shard (shard02), mongoS recognizes:
mongos> db.companies.getIndexes()mongos> db.companies.getIndexes()
|
[ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "vinnie.companies" }, { "v" : 2, "key" : { "firm" : 1 }, "name" : "firm_1", "ns" : "vinnie.companies" }] |
The proposed solution is to recognize the index independent of the shard role.