# ElasticSearch becomes unresponsive **URL:** \ **Category:** Elasticsearch\ **Created:** [April 17, 2012, 12:39pm UTC](https://discuss.elastic.co/t/elasticsearch-becomes-unresponsive/7366 "2012-04-17T12:39:36Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Mattias\_Pfeiffer\_2](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mattias_pfeiffer_2/32/2916_2.png) [@Mattias\_Pfeiffer\_2](https://discuss.elastic.co/u/Mattias_Pfeiffer_2)\ **Post date:** [April 17, 2012, 12:39pm UTC](https://discuss.elastic.co/t/elasticsearch-becomes-unresponsive/7366/1 "2012-04-17T12:39:36Z")
Hi, Over the last few weeks I've seen ES becoming unresponsive. The HTTP interface just hangs until the browser times it out. I'm unable to stop the process via start-stop-daemon. The only effective way I've found to stop elasticsearch is to `kill -9 PID`. When I start the service again, everything works fine. I observed the problem on 0.18.2 after months of successful operation. The ES is a one-node service. I suspected it might be caused by either bad data or a bug, so I upgraded to 0.19.1 without migrating the data and did a fresh re-import of the data on 0.19.1, but I'm still seeing this unwanted behavior. Environment: - Debian squeeze 2.6.32-5-amd64 - java version "1.6.0\_18" - OpenJDK Runtime Environment (IcedTea6 1.8.7) (6b18-1.8.7-2~squeeze1) - ES 0.19.1 and 0.18.2 Running strace with -c when the server is unresponsive returns: % time seconds usecs/call calls errors syscall * * * 48.11 4.088616 711 5748 909 futex 30.17 2.564161 2827 907 epoll\_wait 21.70 1.844104 41911 44 7 restart\_syscall 0.01 0.000634 0 1354 pread 0.00 0.000067 1 75 write 0.00 0.000029 1 47 17 epoll\_ctl 0.00 0.000014 0 262 mprotect 0.00 0.000014 0 62 madvise 0.00 0.000010 0 100 close 0.00 0.000009 0 75 setsockopt 0.00 0.000000 0 76 15 read 0.00 0.000000 0 56 open 0.00 0.000000 0 128 32 stat [... snip...] * * * 100.00 8.497658 9692 1005 total The full and formatted strace summary is available here: [https://gist.github.com/2405701#file\_strace.txt](https://gist.github.com/2405701#file_strace.txt) In a detailed strace I see a lot of entries like this: 15171 \<... futex resumed\> ) = -1 ETIMEDOUT (Connection timed out) Detailed strace is available here: [https://gist.github.com/2405701#file\_strace+details.txt](https://gist.github.com/2405701#file_strace+details.txt) Any idea how to fix this or at least how to debug further? Thanks, Mattias ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [April 19, 2012, 1:22pm UTC](https://discuss.elastic.co/t/elasticsearch-becomes-unresponsive/7366/2 "2012-04-19T13:22:15Z")
Hi, First, can you use a newer version of Java? THe one you use is very old, the latest 1.6 version is update 31. If this does not work, see if you can issue jstack against it when its in this state: [jstack - Stack Trace](http://docs.oracle.com/javase/1.5.0/docs/tooldocs/share/jstack.html) and gist it. Also, if you can monitor its heap usage memory and see if its possibly running out of memory would help (I assume there is nothing in the logs...). -shay.banon On Tue, Apr 17, 2012 at 3:39 PM, Mattias Pfeiffer [mattias@pfeiffer.dk](mailto:mattias@pfeiffer.dk)wrote: > Hi, > > Over the last few weeks I've seen ES becoming unresponsive. The HTTP > interface just hangs until the browser times it out. I'm unable to stop the > process via start-stop-daemon. The only effective way I've found to stop > elasticsearch is to `kill -9 PID`. When I start the service again, > everything works fine. I observed the problem on 0.18.2 after months of > successful operation. The ES is a one-node service. > > I suspected it might be caused by either bad data or a bug, so I upgraded > to 0.19.1 without migrating the data and did a fresh re-import of the data > on 0.19.1, but I'm still seeing this unwanted behavior. > > Environment: > > - Debian squeeze 2.6.32-5-amd64 > - java version "1.6.0\_18" > - OpenJDK Runtime Environment (IcedTea6 1.8.7) (6b18-1.8.7-2~squeeze1) > - ES 0.19.1 and 0.18.2 > > Running strace with -c when the server is unresponsive returns: > > % time seconds usecs/call calls errors syscall > > * * * > > 48.11 4.088616 711 5748 909 futex > 30.17 2.564161 2827 907 epoll\_wait > 21.70 1.844104 41911 44 7 restart\_syscall > 0.01 0.000634 0 1354 pread > 0.00 0.000067 1 75 write > 0.00 0.000029 1 47 17 epoll\_ctl > 0.00 0.000014 0 262 mprotect > 0.00 0.000014 0 62 madvise > 0.00 0.000010 0 100 close > 0.00 0.000009 0 75 setsockopt > 0.00 0.000000 0 76 15 read > 0.00 0.000000 0 56 open > 0.00 0.000000 0 128 32 stat > [... snip...] > > * * * > > 100.00 8.497658 9692 1005 total > > The full and formatted strace summary is available here: > [elasticsearch strace · GitHub](https://gist.github.com/2405701#file_strace.txt) > > In a detailed strace I see a lot of entries like this: > > 15171 \<... futex resumed\> ) = -1 ETIMEDOUT (Connection timed out) > > Detailed strace is available here: > [elasticsearch strace · GitHub](https://gist.github.com/2405701#file_strace+details.txt) > > Any idea how to fix this or at least how to debug further? > > Thanks, > > Mattias ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:32am UTC](https://discuss.elastic.co/t/elasticsearch-becomes-unresponsive/7366/3 "2017-07-06T03:32:02Z")