use dbversity db.nosql.ensureIndex({“mongodb” : 1}) db.rbdms.ensureIndex({“oracle” : 1}) db.newsql.ensureIndex({“memsql” : 1}) sh.enableSharding(“dbversity”) use admin db.runCommand({shardCollection: “dbversity.nosql”, key : {“mongodb”:1}}) db.runCommand({shardCollection: “dbversity.rbdms”, key : {“oracle”:1}}) db.runCommand({shardCollection: “dbversity.newsql”, key : {“memsql”:1}}) sh.startBalancer() sh.isBalancerRunning() sh.getBalancerState() for (var i=0; i
Suppose I’m visiting a web site. I right-click on one of the navigation links and select to open the link in a new window. What should happen? If I’m like most users, I expect the new page to have the…
MognoDB Inc has identified a bug in MongoDB 3.0 where, under very rare circumstances, an integer overflow condition may cause a replica set to become read-only. While this bug does not cause any data loss, it has the potential to cause…
replSetTest is an internal command that is not enabled by default. replSetTest must be enabled by using –setParameter enableTestCommands=1 on the mongod command line. replSetTestcannot be enabled during run-time. > var rst = new ReplSetTest( { name: ‘rsTest’, nodes:…
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MongoDB Sharding is a complex operation for the db cluster and below are the reasons to shard. Whole data doesn’t fit on one server’s storage (Disk Space) Disk IO & CPU Working set doesn’t fit in one server’s RAM Write…
Using $gte and $lt on the shard key fields inside a query will cause it the query to be targeted to only the appropriate shards. However, using the $min and $max query operators (while hinting on the shard key) doesn’t…
Shard key can not exceed 128 characters, if you try so Mongo doesn’t create an Index for that Shard key and as a result such sharded collection without index for sharding key will case performance degradation. mongos> use sharding_test;…
Having the collection empty, when trying to do an upsert using $setOnInsert on a shard key I get the following error: Can’t modify shard key’s value. field: card: 1.0 collection: vizvid.total_video_views mongos> db.dbversity.status() { “sharded” : true, “ns” : “dbfry.dbversity”,…