Hi Otis, Right I didn't restart the JVMs except on the one slave where I was experimenting with using G1GC on the 1.7.0_21 JRE. Also some time ago I made all our caches small enough to keep us from getting OOMs while still having a good hit rate. Our index has about 50 fields which are mostly int IDs and there are some dynamic fields also. These dynamic fields can be used for custom faceting. We have some standard facets we always facet on and other dynamic facets which are only used if the query is filtering on a particular category. There are hundreds of these fields but since they are only for a small subset of the overall index they are very sparsely populated with regard to the overall index. With CMS GC we get a sawtooth on the old generation (I guess every replication and commit causes it's usage to drop down to 10GB or so) and it seems to be the old generation which is the main space consumer. With the G1GC, the memory map looked totally different! I was a little lost looking at memory consumption with that GC. Maybe I'll try it again now that the index is a bit smaller than it was last time I tried it. After four days without running an optimize now it is 21GB. BTW our indexing speed is mostly bound by the DB so reducing the segments might be ok...
Here is a quick snapshot of one slaves memory map as reported by PSI-Probe, but unfortunately I guess I can't send the history graphics to the solr-user list to show their changes over time: Name Used Committed Max Initial Group Par Survivor Space 20.02 MB 108.13 MB 108.13 MB 108.13 MB HEAP CMS Perm Gen 42.29 MB 70.66 MB 82.00 MB 20.75 MB NON_HEAP Code Cache 9.73 MB 9.88 MB 48.00 MB 2.44 MB NON_HEAP CMS Old Gen 20.22 GB 30.94 GB 30.94 GB 30.94 GB HEAP Par Eden Space 42.20 MB 865.31 MB 865.31 MB 865.31 MB HEAP Total 20.33 GB 31.97 GB 32.02 GB 31.92 GB TOTAL And here's our current cache stats from a random slave: name: queryResultCache class: org.apache.solr.search.LRUCache version: 1.0 description: LRU Cache(maxSize=488, initialSize=6, autowarmCount=6, regenerator=org.apache.solr.search.SolrIndexSearcher$3@461ff4c3) stats: lookups : 619 hits : 36 hitratio : 0.05 inserts : 592 evictions : 101 size : 488 warmupTime : 2949 cumulative_lookups : 681225 cumulative_hits : 73126 cumulative_hitratio : 0.10 cumulative_inserts : 602396 cumulative_evictions : 428868 name: fieldCache class: org.apache.solr.search.SolrFieldCacheMBean version: 1.0 description: Provides introspection of the Lucene FieldCache, this is **NOT** a cache that is managed by Solr. stats: entries_count : 359 name: documentCache class: org.apache.solr.search.LRUCache version: 1.0 description: LRU Cache(maxSize=2048, initialSize=512, autowarmCount=10, regenerator=null) stats: lookups : 12710 hits : 7160 hitratio : 0.56 inserts : 5636 evictions : 3588 size : 2048 warmupTime : 0 cumulative_lookups : 10590054 cumulative_hits : 6166913 cumulative_hitratio : 0.58 cumulative_inserts : 4423141 cumulative_evictions : 3714653 name: fieldValueCache class: org.apache.solr.search.FastLRUCache version: 1.0 description: Concurrent LRU Cache(maxSize=280, initialSize=280, minSize=252, acceptableSize=266, cleanupThread=false, autowarmCount=6, regenerator=org.apache.solr.search.SolrIndexSearcher$1@143eb77a) stats: lookups : 1725 hits : 1481 hitratio : 0.85 inserts : 122 evictions : 0 size : 128 warmupTime : 4426 cumulative_lookups : 3449712 cumulative_hits : 3281805 cumulative_hitratio : 0.95 cumulative_inserts : 83261 cumulative_evictions : 3479 name: filterCache class: org.apache.solr.search.FastLRUCache version: 1.0 description: Concurrent LRU Cache(maxSize=248, initialSize=12, minSize=223, acceptableSize=235, cleanupThread=false, autowarmCount=10, regenerator=org.apache.solr.search.SolrIndexSearcher$2@36e831d6) stats: lookups : 3990 hits : 3831 hitratio : 0.96 inserts : 239 evictions : 26 size : 244 warmupTime : 1 cumulative_lookups : 5745011 cumulative_hits : 5496150 cumulative_hitratio : 0.95 cumulative_inserts : 351485 cumulative_evictions : 276308 -----Original Message----- From: Otis Gospodnetic [mailto:otis.gospodne...@gmail.com] Sent: Saturday, June 15, 2013 5:52 AM To: solr-user@lucene.apache.org Subject: Re: yet another optimize question Hi Robi, I'm going to guess you are seeing smaller heap also simply because you restarted the JVM recently (hm, you don't say you restarted, maybe I'm making this up). If you are indeed indexing continuously then you shouldn't optimize. Lucene will merge segments itself. Lower mergeFactor will force it to do it more often (it means slower indexing, bigger IO hit when segments are merged, more per-segment data that Lucene/Solr need to read from the segment for faceting and such, etc.) so maybe you shouldn't mess with that. Do you know what your caches are like in terms of size, hit %, evictions? We've recently seen people set those to a few hundred K or even higher, which can eat a lot of heap. We have had luck with G1 recently, too. Maybe you can run jstat and see which of the memory pools get filled up and change/increase appropriate JVM param based on that? How many fields do you index, facet, or group on? Otis -- Performance Monitoring - http://sematext.com/spm/index.html Solr & ElasticSearch Support -- http://sematext.com/ On Fri, Jun 14, 2013 at 8:04 PM, Petersen, Robert <robert.peter...@mail.rakuten.com> wrote: > Hi guys, > > We're on solr 3.6.1 and I've read the discussions about whether to optimize > or not to optimize. I decided to try not optimizing our index as was > recommended. We have a little over 15 million docs in our biggest index and > a 32gb heap for our jvm. So without the optimizes the index folder seemed to > grow in size and quantity of files. There seemed to be an upper limit but > eventually it hit 300 files consuming 26gb of space and that seemed to push > our slave farm over the edge and we started getting the dreaded OOMs. We > have continuous indexing activity, so I stopped the indexer and manually ran > an optimize which made the index become 9 files consuming 15gb of space and > our slave farm started having acceptable memory usage. Our merge factor is > 10, we're on java 7. Before optimizing, I tried on one slave machine to go > with the latest JVM and tried switching from the CMS GC to the G1GC but it > hit OOM condition even faster. So it seems like I have to continue to > schedule a regular optimize. Right now it has been a couple of days since > running the optimize and the index is slowly growing bigger, now up to a bit > over 19gb. What do you guys think? Did I miss something that would make us > able to run without doing an optimize? > > Robert (Robi) Petersen > Senior Software Engineer > Search Department