MongoDB query issue on cluster

Question

I have created cluster with 2 shards. Please check my shards status below.

shards:
        {  "_id" : "shard0000",  "host" : "172.20.1.66:27021" }
        {  "_id" : "shard0001",  "host" : "172.20.1.66:27022" }
  balancer:
        Currently enabled:  yes
        Currently running:  no
        Failed balancer rounds in last 5 attempts:  0
        Migration Results for the last 24 hours:
                No recent migrations
  databases:
        {  "_id" : "admin",  "partitioned" : false,  "primary" : "config" }
        {  "_id" : "symfony",  "partitioned" : false,  "primary" : "shard0000" }
        {  "_id" : "testDB",  "partitioned" : true,  "primary" : "shard0001" }
                testDB.products
                        shard key: { "_id" : "hashed" }
                        chunks:
                                shard0001       2
                        { "_id" : { "$minKey" : 1 } } -->> { "_id" : NumberLong(0) } on : shard0001 Timestamp(1, 0)
                        { "_id" : NumberLong(0) } -->> { "_id" : { "$maxKey" : 1 } } on : shard0001 Timestamp(1, 1)

I have inserted more than 100000 docs and tried to fetch data using query.

db.products.find();

It is returning error as shown below.

Error: error: {
        "$err" : "setShardVersion failed shard: shard0001:172.20.1.66:27022 { oldVersion: Timestamp 0|0, oldVersionEpoch: ObjectId('000000000000000000000000'), ns: \"testDB.products\", version: Timestamp 1000|1, versionEpoch: ObjectId('5668170dbd53962a250383f8'), globalVersion: Timestamp 0|0, globalVersionEpoch: ObjectId('000000000000000000000000'), reloadConfig: true, ok: 0.0, errmsg: \"could not refresh metadata for testDB.products with requested shard version 1|1||5668170dbd53962a250383f8, stored shard version is 0|0||00000000000000...\" }",
        "code" : 10429,
        "shard" : "shard0001"
}

Can some one help me to resolve this issue.

Answer 1

I have seen this error happening when some of the servers could not contact the config servers. Please make sure:

• That your config server(s) are up and running.
• That your mongos instance can contact the config server(s).
• That all mongod instances can contact the config server(s).

Also, look into the logs of all servers in your setup and look for errors.