Re: Hadoop Certification

2016-09-04 Thread Marcin Tustin
Honestly, this is going to depend on the jobs you are targeting and the local market. For example, in the New York market I'm not aware of any job listings that mention certification as even a nice to have. For someone who wants to become a Hadoop admin it might be at least mildly valuable. I thi

Re: Building a distributed system

2016-07-19 Thread Marcin Tustin
the Hadoop (or some other) infrastructure in a > simple way to prevent us having to write a scheduler, database schema > etc.? We can do that but it seems to be solving a problem that has already > been solved many times. > > Thanks again, > > Richard > > > *From:* Ravi

Re: Building a distributed system

2016-07-18 Thread Marcin Tustin
I think you're confused as to what these things are. The fundamental question is do you want to run one job on sub parts of the data, then stitch their results together (in which case hive/map-reduce/spark will be for you), or do you essentially already have splitting to computer-sized chunks figu

Re: HDFS2 vs MaprFS

2016-06-05 Thread Marcin Tustin
The namenode architecture is a source of fragility in HDFS. While a high availability deployment (with two namenodes, and a failover mechanism) means you're unlikely to see service interruption, it is still possible to have a complete loss of filesystem metadata with the loss of two machines. Seco

Re: Resource manager is down

2016-05-04 Thread Marcin Tustin
The biggest win I've seen for stability of hadoop components is to give them their own hard disks; or alternatively their own hosts. Obviously, you'll also want to check the usual suspects or resource and processor contention. On Wed, May 4, 2016 at 3:59 PM, Anandha L Ranganathan wrote: > The R

About Yarn Capacity Scheduler and Fair Scheduler

2016-04-15 Thread Marcin Tustin
This is what the capacity scheduler is for. See my article on working around a particular bug in the current version of the capacity scheduler https://medium.com/handy-tech/practical-capacity-scheduling-with-yarn-28548ae4fb88 Note the part on user limits. On Friday, April 15, 2016, Todd > wrote:

Configuring capacity scheduling in the face of YARN-3216

2016-04-06 Thread Marcin Tustin
Many people will be aware of YARN-3216 ( https://issues.apache.org/jira/browse/YARN-3216). In short, the capacity scheduler calculates all values only off the default label and queue. My colleague Dave and I (and really mostly Dave!) configured our cluster to work pretty much as desired even with

Re: Yarn with CapacityScheduler will only schedule two applications - open to consultants today

2016-03-02 Thread Marcin Tustin
"yarn" hence 2 if not for a given partition only one would have run (if the > am resource is less than the mimium size CS allows atleast 1 am to run) > > Given that you have already identified the issue, what more are you > expecting ? > > Regards, > + Naga > --

Yarn with CapacityScheduler will only schedule two applications - open to consultants today

2016-03-02 Thread Marcin Tustin
Hi All, We're hitting this issue. If you're a consultant with capacity today (2 March 2016 EST in New York) please feel free to contact me on or off list. In terms of stack, we're using Yarn 2.7.1.2.3 from the latest Hortonworks distribution. It's possible we're hitting this bug: https://issues.a

Re: Can't run rebalancer because it thinks another is running

2016-01-05 Thread Marcin Tustin
; > https://issues.apache.org/jira/browse/AMBARI-13946 > > If your hdfs-site.xml contains the "non-HA properties" described in that > issue, then a viable workaround would be to remove those properties. > > --Chris Nauroth > > From: Anu Engineer > Date: Monday, January

Can't run rebalancer because it thinks another is running

2015-12-30 Thread Marcin Tustin
Hi, I'm running HDFS in HA mode. I can't run the rebalancer because I get this message: java.io.IOException: Another Balancer is running.. Exiting ... Dec 31, 2015 12:22:09 AM Balancing took 1.159 seconds Any suggestions as to why that might be; and if it's the obvious that it's running elsewhe

HDFS HA Namenodes crash all the time

2015-12-19 Thread Marcin Tustin
Hi All, We have just switched over to HA namenodes with ZK failover, using HDP-2.3.0.0-2557 (HDFS 2.7.1.2.3). I'm looking for suggestions as to what to investigate to make this more stable. Before we went to HA our namenode was reasonably stable. Now, the namenodes are crashing multiple times a d