Top Knowledge Articles

How to manage MFS memory usage

When MapR's warden service starts on a node it calculates the service memory allocation based on the configured roles and the configuration ...
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How to handle core files found in MapR

When a core file is found under /opt/cores on a node MapR raises an alarm to alert an administrator that a service has possibly exited unexpectedly. This alarm is logged as NODE_ALARM_CORE_PRESENT...
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Configuring and Deploying Ganglia with MapR

Ganglia is a popular open-source monitoring tool that can be used to monitor and aggregate metrics from multiple data sources and clusters. It is typically used to monitor system resources such as CPU, memory, disk IO, network utilization,etc. across many systems...
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How to Diagnose Slow Performance of Mirroring in MapR

MapR provides the capability to mirror a volume from one MapR cluster to a remote cluster to provide a backup for disaster recovery purposes. In the event there is a total loss of function in the source cluster the mirrored dataset can be recovered from the mirror volume in the remote cluster...
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Top MapR Support Blogs

Best Practices for YARN Resource Management

In this blog post, I will discuss best practices for YARN resource management. The fundamental idea of MRv2(YARN) is to split up the two major functionalities; resource management and job scheduling/monitoring, into separate daemons...
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Memory Management for Clusters Running Both MR1 and MR2 Services

In this blog post, you'll learn how memory is sliced and diced from the time you start warden, how memory is allocated to each MapR service installed on the node, and what memory is made available for MR1/MR2 for running jobs. ....
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Five Steps to Avoiding Java Heap Space Errors

Keeping these five steps in mind can save you a lot of headaches and avoid Java heap space errors....
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Recent Patch Release

Here are some of our latest patches and the fixes which are included. To review the complete list for each, just click on the version you are running.

Download our latest patches

  • 5.0.0
    • 22301 - When all_squash is used , files above 64K not getting created in loopbacknfs
    • 21900 - MFS not updating stale container count
    • 22300 - Windows - compile error in api_support.cc
    • 21731 - TaskTracker starts timer for child JVM ping before launching child JVM
    • 21638 - memory corruption in MAPR DB C API causes segmentation fault
    • 20658 - MCS hanging because of Alarm View
    • 20161 - Hbase regionservers going to Freeze state as compaction threads stuck for long time..
  • 4.1.0
    • 21731 - TaskTracker starts timer for child JVM ping before launching child JVM
    • 21638 - memory corruption in MAPR DB C API causes segmentation fault
    • 20658 - MCS hanging because of Alarm View
    • 20671 - Mirror intravolume resync must use fast resync slots when there is no change
    • 21171 - mfs is restarting often due to hang
  • 4.0.2
    • 21731 - TaskTracker starts timer for child JVM ping before launching child JVM
    • 20658 - MCS hanging because of Alarm View
    • 21407 - maprcli dump restore hangs for standard volume
    • 20671 - Mirror intravolume resync must use fast resync slots when there is no change
  • 4.0.1
    • 21731 - TaskTracker starts timer for child JVM ping before launching child JVM
    • 20658 - MCS hanging because of Alarm View
Latest News

MapR Software 3.x End of Support
This release is coming to the end of its Support lifecycle. To get more details click here.

Read the EOS   

 
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