Re: I got errors from hdfs about DataStreamer Exceptions.

2011-04-16 Thread 茅旭峰
I double checked the cluster, all of the disk have plenty of free space. I could not put any data into the cluster. The cluster summary shows == Cluster Summary***1987209 files and directories, 1993327 blocks = 3980536 total. Heap Size is 4.2 GB / 5.56 GB (75%) * Configured Capacity : 120.88 TB

Re: Hadoop 0.21.0 and eclipse europa compatibility issue

2011-04-16 Thread 顾荣
Hi, You can try hadoop-0.20.2 with Eclipse 3.3,that is recommended. Regards Walker Gu. 2011/4/15 Vandana Kanchanapalli vandana@gmail.com Hi, I am facing this problem with eclipse europa version. I am using hadoop-0.21.0. After adding the hadoop-eclipse plugin to the IDE, I started to

Re: io.sort.mb based on HDFS block size

2011-04-16 Thread 顾荣
Hi Shrinivas, sry for this late reply. yeah,I can understand what you mean.I also don't mean the io.sort.mb is equal to the block size.The point is that the data in buffer are spilled to HDFS by several times,and each time just spill a little.Before writing to HDFS ,the spilled data will be

Re: Estimating Time required to compute M/Rjob

2011-04-16 Thread Stephen Boesch
You could consider two scenarios / set of requirements for your estimator: 1. Allow it to 'learn' from certain input data and then project running times of similar (or moderately dissimilar) workloads. So the first steps could be to define a couple of relatively small control M/R

Re: Estimating Time required to compute M/Rjob

2011-04-16 Thread Stephen Boesch
some additional thoughts about the the 'variables' involved in characterizing the M/R application itself. - the configuration of the cluster for numbers of mappers vs reducers compared to the characteristics (amount of work/procesing) required in each of the map/shuffle/reduce stages

Re: Estimating Time required to compute M/Rjob

2011-04-16 Thread Ted Dunning
Sounds like this paper might help you: Predicting Multiple Performance Metrics for Queries: Better Decisions Enabled by Machine Learning by Ganapathi, Archana, Harumi Kuno, Umeshwar Daval, Janet Wiener, Armando Fox, Michael Jordan, David Patterson http://radlab.cs.berkeley.edu/publication/187

Map Result Caching

2011-04-16 Thread DoomUs
I'd like to see if caching Map outputs is worth the time. The idea is that for certain jobs, many of the Map tasks will do the same thing they did last time they were run, for instance a monthly report with vast data, but very little changing data. So every month the job is run, and some % of