New In This Release
- New Alarm: NODE_ALARM_METRICS_WRITE_PROBLEM.
- Architectural changes to the handling of Hadoop configuration files
Default mapred Parameters, and
core-site.xml. These changes are transparent to developers and administrators; continue to specify custom values for parameters in those files as normal.
- New utility: hadoop conf to display configuration information for a node.
- (Issue 9017) Multi-thread timing issue no longer results in null pointer exceptions.
- (Issue 9044) Multi-thread issue timing issue with the Fair Scheduler no longer results in null pointer exceptions.
- (Issue 9046) The
configure-common.shscript now uses a default path when
mapred-site.xmldoes not specify the path.
- (Issue 9075) The
hadoop confCLI tool checks key values and can dump the entire configuration.
- (Issue 9067) JobTrackers start correctly after a manual rolling upgrade to this version.
MCS and CLI
- (Issue 9080) The
diskremove.shscript now correctly invokes
- (Issue 9037) MapReduce task attempts connect more reliably to the HBase Regionserver. Improved performance in
fileclient, particularly in HBase random read operations.
In some cases, Map/Reduce preemption may not work with Map Task prefetch and Expresslane. MapR recommends using prefetch, preemption and expresslane mutually exclusively.
The bug https://issues.apache.org/jira/browse/HIVE-2907 is not yet fixed in MapR's release. It may cause the dropping of a table with a large number of partitions to fail due to an out-of-memory error.
There are no obvious indications when a MapR license expires, except the degradation of services to the non-licensed level. The workaround is to pay attention to License expiration alarms before the actual expiry.
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.
Map/Reduce and Hadoop Patches Integrated Since Last Release
The 2.1.1 release of the MapR distribution of Hadoop has not integrated any Apache Hadoop patches that are not included in the 2.1.0 release of the MapR distribution for Hadoop.