History of MySQL
Inception MySQL was created by a Swedish company MySQL AB in 1995. The developers of the platform were Michael Widenius (Monty), David Axmark and Allan Larsson. The foremost purpose was to provide efficient and reliable data management options to…
mtool for MongoDB Diagnostics
mtools mtools is a collection of helper scripts to parse and filter MongoDB log files (mongod, mongos), visualize log files and quickly set up complex MongoDB test environments on a local machine. Installation procedure :- Step 1:…
MongoDB as pure In-memory
MongoDB as an pure in-memory database, meaning that the data is not stored on disk at all. This can be super useful for applications like: A write-heavy cache in front of a slower RDBMS system Embedded systems PCI compliant systems…
mdiag script for gathering MongoDB’s system & h/w diagnostic info.
mdiag is a shell script which will gather a wide variety of system and hardware diagnostic information of the MongoDB server. Please see below for how it works. mdiag shell script: [Lab root @ hostname /tmp]# cat mdiag.sh #!/bin/sh…
Importing large flat files into mongoDB
This is a very basic technique, but that’s how I like to start. I will also show a couple tricks when working with large data files. Editing large files Let’s assume you have a large data file, approximately 60MB with…
Monitoring Hadoop from the browser
Hadoop provides two web interfaces that you should become familiar with, one for HDFS and the other for MapReduce. Both are useful in pseudo-distributed mode and are critical tools when you have a fully distributed setup. The HDFS web UI…
How to drop a field from a MongoDB document ?
For people coming from RDBMS you must be remembering the alter table command for dropping/adding columns in a table. In MongoDB it is possible to do this operation on some of the documents (rows) or all documents together. There is…
Knowing MongoDB opLog
Replication gives you hot backups, read scaling, and all sorts of other goodness. If you know how it works you can get a lot more out of it, from how it should be configured to what you should monitor to…
SSH issues with Incomplete SOE Build VMs
Do you have issues with you SSH in your lab/test VMs which has no proper builds and thus it’s effecting SSH Tectia functionality. No issues, below works for me – please have a try. Not sure how far this is…
MongoDB graceful shutdown script.
MongoDB graceful shutdown script. [root@hostname bin]$ cat new_shutdown.sh #!/bin/bash BIN=/tmp/mongodb/bin DB=admin HOST=`hostname` cd $BIN MONGOPID=`ps -ef | egrep ‘mongod|mongos’ | grep -v egrep | awk ‘{print $2}’` if [ -z $MONGOPID ]; then echo “There are no Mongo processes are…