= MongoDb/Performance =
 * [[attachment:MongoDB-Performance-Best-Practices.pdf]] https://neotan.github.io/images/media/MongoDB-Performance-Best-Practices.pdf

== Indicate in connection string to not use primary server in cluster ==
 * mongodb://user:pass@urls/db?readPreference=secondary&readPreferenceTags=nodeType:ANALYTICS&readConcernLevel=local

=== Slow / Long running queries ===
 * * $ mongo 10.32.2.4 --authenticationDatabase admin --username test --password mypass
 * > db.currentOp()
 * > db.currentOp({"secs_running": {$gte: 3}})

 * Count documents in <db> <collection>
   * use <db>;
   * db.<collection>.count()
 
 * DB locks
   * > db.serverStatus().globalLock
   * > db.serverStatus().locks

 * DB version , want > 3.2 wiretiger document level locking
   * > db.version()

 * DB memory usage should be less than ram
   * > db.serverStatus().mem
   * > db.serverStatus().wiredTiger.cache

 * Check number of connections
   * db.serverStatus().connections

 * Check indexs on a collection
   * db.<collection>.getIndexes()

== From mongodb atlas help - how to view active connections ==
 * view active connections in shell {{{
db.currentOp(true).inprog.forEach( function(op) { if(op.active = true && op.client != undefined) { var miniOp = { client : op.client, description : op.desc }; printjson(miniOp);}  } );

}}}
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CategoryPerformance