Thanks! Because of your information, I managed to find out that my crashes have to do with the somewhat standard 'Too many open files'. I added some 'close' and 'disconnect' to my InputStreams and HttpURLConnections, but that only works up to a certain point. The strange thing is that I do execute 'ulimit -n 32768', but I'm thinking it somehow 'won't' stick. The other alternative is that Hadoop is using 32768 file descriptors, but that seems a bit over the top, as I'm using at most 200 threads (each of which only sets up one HttpURLConnection).
Suggestions are welcome :-) On Mon, Aug 3, 2009 at 3:58 PM, Jason Venner <[email protected]> wrote: > That generally means that the process that is running the task, crashed. > The actual map/reduce task is run in a separate jvm by the task tracker, > and that JVM is exiting abnormally. > This used to happen to my jobs quite a bit when they were using a buggy > native library via jni. > > If you are trying to use the colorspace transforms via the java imaging > APIs, it is not thread safe (at least through 1.6.10 under linux). > > There may be additional information available in the per task logs. > > 2009/8/3 Mathias De Maré <[email protected]> > > I'm getting a rather cryptic error while running a Map job with >> MultithreadedMapper (no idea if it has anything to do with the >> MultithreadedMapper). >> It only occurs sometimes, occurs at different times during the Map >> (sometimes at the start, sometimes at a random location), and it doesn't >> really give any information. >> >> Task Id : attempt_200908031207_0009_m_000000_0, Status : FAILED >> java.io.IOException: Task process exit with nonzero status of 255. >> at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:418) >> >> I'm a bit at a loss. The only results I'm finding from Google are a few >> other people who have had the same problem, but nobody with a solution. >> >> Mathias De Maré >> > > > > -- > Pro Hadoop, a book to guide you from beginner to hadoop mastery, > http://www.amazon.com/dp/1430219424?tag=jewlerymall > www.prohadoopbook.com a community for Hadoop Professionals >
