Linux Leap Second Bug
A bug in the
hrtimer component of the Linux
ntp subsystem was discovered when the leap second was applied to Coordinated Universal Time (UTC) on June 30, 2012 at 23:59:60 UTC. To work around the bug, MapR recommends running the following command as
root on all nodes:
Wait a day before re-enabling NTP:
Inline setup is a setting that causes each job's setup task to run as a thread directly inside of the JobTracker instead of being forked out as a separate task by a TaskTracker. This means that jobs that need a setup task will start running faster in some cases because they don't need to wait for the TaskTrackers to get scheduled and then run the setup task.
MapR recommends turning off inline setup (
mapred-site.xml) on production clusters, because it is dangerous to have the JobTracker execute user-defined code as the privileged JT user (root). If you originally installed version 1.2.7 or earlier, inline setup defaults to
true and you should set it to
false by adding the following to
MapR provides the following packages:
- Apache Hadoop 0.20.2
- Flume 0.9.4
- Hbase 0.90.6
- Hive 0.7.1
- Mahout 0.5
- Oozie 3.0.0
- Pig 0.9.0
- Sqoop 1.3.0
- Whirr 0.3.0
New in This Release
- Support for SUSE Linux
- CLDB enhancements to improve reliability, scalabilty and performance
- Fixes in the MapReduce layer related to security and data integrity
- FSCK performance and logging improvements
- Updates to MapR storage services layer to improve performance, security and stability
- Support for whitelist of subnets MapR-FS will accept requests from
- Support for Hbase 0.90.6
- NFS improvements to increase performance, reliability and failure recovery
- Miscellaneous defect fixes to rolling upgrade and the MapR GUI
- MapR now works with Accumulo
When a node's IP number is reassigned to another node, remote procedure calls are misdirected to the wrong node. This can result in widespread errors affecting any system that use the RPC binding layer, including container resync operations that never finish or the creation of several superfluous containers. Restart the cluster to clear this condition.
If you use the latest version of any browser to view the MCS, the CLDB, HBase, JobTracker, and job log pages do not load when you click on the respective links. As a workaround, use the following instructions to disable mixed-content-blocking in your browser:
Scroll to the bottom of the screen, and click Show all content. The page refreshes and displays mixed content.
- At the top of the page, to the left of the address bar, click (the shield icon).
- In the pop-up window that appears, click the down arrow next to "Keep Blocking", and select Disable Protection on This Page. The page refreshes and displays mixed content. The shield icon is replaced with a warning symbol to indicate that the page is displaying both secure and non-secure items.
- Click (the shield icon) on the right side of the address bar.
- In the icon dialog box, click Load anyway. The page refreshes and displays mixed content. The URL in the address bar shows https crossed out to indicate that the page is displaying both secure and non-secure items.