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jirapos...@reviews.apache.org commented on HBASE-4027: ------------------------------------------------------ bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > conf/hbase-env.sh, lines 44-45 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28125#file28125line44> bq. > bq. > Is MaxDirectMemorySize determinable on the running jvm? Could we make the offheapcachesize config as a percentage of the direct memory size like we have for memstore/blockcache today? (default of 0.95 or something would make it so it never really has to be set for most cases... and i'm not sure what exactly "a bit above the off heap cache size" is) I haven't figured out a way. Just asked StackOverflow - hopefully they'll have an answer. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/BlockCacheTestUtils.java, line 2 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28127#file28127line2> bq. > bq. > 2011 Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/CacheStats.java, line 1 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28128#file28128line1> bq. > bq. > license Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/BlockCacheTestUtils.java, line 41 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28127#file28127line41> bq. > bq. > whitespace Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/CacheStats.java, line 5 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28128#file28128line5> bq. > bq. > class comment Added bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java, line 39 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28129#file28129line39> bq. > bq. > Would it make sense to have DoubleBlockCache be more generic? Does it need to be fixed with these two types or could it take two BlockCache's and they are executed in the order they are given in (just need to be clear in doc). bq. > bq. > If this was generic, it could be reused for various multi-level caches (like an underlying cache with compressed blocks and one above it with uncompressed blocks) It can be made more generic easily. I just haven't done it. Will do though - just create a constructor that takes two BlockCaches? bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java, line 66 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28129#file28129line66> bq. > bq. > longer than 80 chars fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java, lines 77-79 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28129#file28129line77> bq. > bq. > This seems like a behavior that we may not always want. bq. > bq. > If we made this class generic, could we have some kind of policy we initiate it with? (like default cache in level one, if accessed in level one, cache in level two, etc?) bq. > bq. > we're going to always be double-storing anything so that the offHeap true capacity is (totalOffHeap - totalOnHeap). in some cases, we might want to cache on heap first and then if evicted we cache off heap, or maybe we want it to work more like the existing LRU (first read goes into off heap, second read upgrades it to the on heap cache and removes from the off heap) I was thinking of sending all initial caches to the off heap cache, giving it an inbuilt scan resistance, but LRUBlockCache already does partitioning to deal with scans. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java, line 115 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28129#file28129line115> bq. > bq. > this is going to make for some weird stats? seems like we may need to actually expose the stats of each underlying cache rather than both? (or both and separate). it's going to be difficult to understand what's happening when the hit and eviction stats cover both. The idea was the combined evicted stats of both, but yeah, CacheStats are implemented for both LruBlockCache and SlabCache, so exposing both might be a good idea. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SingleSizeCache.java, line 74 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28132#file28132line74> bq. > bq. > huh? Just a typo. Fixed. Don't know why that line is there. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SingleSizeCache.java, line 84 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28132#file28132line84> bq. > bq. > line > 80 chars fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, lines 122-125 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line122> bq. > bq. > seems like an odd behavior. this method is kinda non-deterministic from the caller POV, we have no idea whether this passed or failed If the size of the item being cached is too big to fit into any slab, we can't cache it. Again, I'm moving away from MemCached's model, so this should work better. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, line 151 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line151> bq. > bq. > is this really a cache miss? this cache will never take this block. Good point. Taking that part out. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, line 155 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line155> bq. > bq. > but here we need to check for null and increment cache miss rather than hit if it is null Yup, doing so as well. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, lines 170-173 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line170> bq. > bq. > this non-javadoc comment is not necessary, just the @Override has been normal format in hbase Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, line 269 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line269> bq. > bq. > should this really be a bunch of INFO logs? Could we have these exported as metrics instead? Will take care of this next pass. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabItemEvictionWatcher.java, line 1 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28135#file28135line1> bq. > bq. > license added. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java, lines 374-375 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28137#file28137line374> bq. > bq. > formatting looks a little strange here (missing spaces and such) fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSingleSlabCache.java, line 28 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28138#file28138line28> bq. > bq. > This test looks more specific than testing "the concurrent LruBlockCache" Woah, typo, fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSingleSlabCache.java, line 34 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28138#file28138line34> bq. > bq. > you are missing a space here and throughout this file and some others... our format is to always have a space before a { fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSlab.java, line 1 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28139#file28139line1> bq. > bq. > license added. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSingleSlabCache.java, line 2 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28138#file28138line2> bq. > bq. > 2011 Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java, line 376 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28137#file28137line376> bq. > bq. > line > 80 chars Fixed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, lines 63-65 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line63> bq. > bq. > Why these ratios? At the least, this should all be configurable (even if just in code and undocumented). bq. > bq. > Do we need to always pre-allocate everything and determine the block/slab sizes and all that? The design seems inflexible because it's all determine during construction rather than being adaptive. bq. > bq. > I'm okay with the first iteration not being awesome and auto-tuning but this layered cache design seems to make it hard to change anything once it's instantiated. Its sort of expensive to change cache sizes with DirectByteBuffer after instantiation. I have a plan to restructure this away from MemCached's model though. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java, line 37 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28129#file28129line37> bq. > bq. > whitespace here and throughout this file Removed. bq. On 2011-07-29 17:41:50, Jonathan Gray wrote: bq. > src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java, line 48 bq. > <https://reviews.apache.org/r/1214/diff/1/?file=28134#file28134line48> bq. > bq. > I'm not totally clear on why the SlabCache contains a bunch of SingleSizeCaches. Why do you need to layer BlockCaches on top of BlockCaches? You'll have one slab per size rather than one cache per size? Can you not pass the right evictor callback in so it goes back to the right slab? I'm using MemCached's allocation model - although I have one written that does it in a wholly different manner. But MemCached gets around fragmentation by allocating a certain range of sizes to a Single Slab. If something is smaller than the max size of a particular slab, the extra space is just wasted. Each SingleSizeCache can cache things up to a certain size. Things above that size cannot be cached, and things below that size will waste space. - Li ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/1214/#review1211 ----------------------------------------------------------- On 2011-07-30 00:39:48, Li Pi wrote: bq. bq. ----------------------------------------------------------- bq. This is an automatically generated e-mail. To reply, visit: bq. https://reviews.apache.org/r/1214/ bq. ----------------------------------------------------------- bq. bq. (Updated 2011-07-30 00:39:48) bq. bq. bq. Review request for hbase, Todd Lipcon, Ted Yu, Michael Stack, Jonathan Gray, and Li Pi. bq. bq. bq. Summary bq. ------- bq. bq. Review request - I apparently can't edit tlipcon's earlier posting of my diff, so creating a new one. bq. bq. bq. This addresses bug HBase-4027. bq. https://issues.apache.org/jira/browse/HBase-4027 bq. bq. bq. Diffs bq. ----- bq. bq. conf/hbase-env.sh 2d55d27 bq. src/main/java/org/apache/hadoop/hbase/io/hfile/BlockCache.java 509121d bq. src/main/java/org/apache/hadoop/hbase/io/hfile/BlockCacheTestUtils.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/CacheStats.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/LruBlockCache.java ecab7ca bq. src/main/java/org/apache/hadoop/hbase/io/hfile/SimpleBlockCache.java 150f54f bq. src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SingleSizeCache.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/slab/Slab.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabItemEvictionWatcher.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1d5e3fa bq. src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java b600020 bq. src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSingleSlabCache.java PRE-CREATION bq. src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSlab.java PRE-CREATION bq. src/test/java/org/apache/hadoop/hbase/io/hfile/slab/TestSlabCache.java PRE-CREATION bq. bq. Diff: https://reviews.apache.org/r/1214/diff bq. bq. bq. Testing bq. ------- bq. bq. Ran benchmarks against it in HBase standalone mode. Wrote test cases for all classes, multithreaded test cases exist for the cache. bq. bq. bq. Thanks, bq. bq. Li bq. bq. > Enable direct byte buffers LruBlockCache > ---------------------------------------- > > Key: HBASE-4027 > URL: https://issues.apache.org/jira/browse/HBASE-4027 > Project: HBase > Issue Type: Improvement > Reporter: Jason Rutherglen > Assignee: Li Pi > Priority: Minor > Attachments: 4027-v5.diff, 4027v7.diff, HBase-4027 (1).pdf, > HBase-4027.pdf, hbase-4027v6.diff, slabcachepatch.diff, > slabcachepatchv2.diff, slabcachepatchv3.1.diff, slabcachepatchv3.2.diff, > slabcachepatchv3.diff, slabcachepatchv4.5.diff, slabcachepatchv4.diff > > > Java offers the creation of direct byte buffers which are allocated outside > of the heap. > They need to be manually free'd, which can be accomplished using an > documented {{clean}} method. > The feature will be optional. After implementing, we can benchmark for > differences in speed and garbage collection observances. -- This message is automatically generated by JIRA. 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