EVENTS / SCHEDULERS in MySQL

By Prasad Khode

MySQL event is a process that is performed  affecting the data on occurrence of certain specified conditions or at a scheduled time. Events are not like triggers which run in response to a change in data . Events  are scheduled to run any number of times like the cron  job is run.

MySQL Events have been added from version 5.1.6 MySQL. Event scheduler is a process that runs in background and looks for events to execute. Before we create or schedule an event in MySQL, we need to first verify whether i event-scheduler is enabled, by default it is OFF in MySQL.

To check whether scheduler is enabled or not, use the following command: (more…)

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Configure Apache Phoenix in CDH 5.4

By Prasad Khode

Apache Phoenix is an open source, relational database layer on top of noSQL store such as Apache HBase. Phoenix provides a JDBC driver that hides the intricacies of the noSQL store enabling users to create, delete, and alter SQL tables, views, indexes, and sequences; upsert and delete rows singly and in bulk; and query data through SQL.

Installation:
Following are the steps that need to be followed to configure Apache Phoenix in Cloudera Distribution for Hadoop (CDH)

1. Login to Cloudera Manager, click on Hosts, then Parcels.
2. Select Edit Settings.
3. Click the + sign next to an existing Remote Parcel Repository URL, and add the URL: http://archive.cloudera.com/cloudera-labs/phoenix/parcels/1.0/ Click Save Changes.
4. Select Hosts, then Parcels.
5. In the list of Parcel Names, CLABS_PHOENIX is now available. Select it and choose Download.
6. The first cluster is selected by default. To choose a different cluster for distribution, select it. Find CLABS_PHOENIX in the list, and click Distribute.
7. If you to use secondary indexing, add the following to the hbase-site.xml advanced configuration snippet. Go to the HBase service, click Configuration, and choose/search for HBase Service Advanced Configuration Snippet (Safety Valve) for hbase-site.xml. Paste in the following XML, then save the changes.

8. Restart the HBase service.

Using Apache Phoenix Utilities: (more…)

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