> On July 10, 2020, 8:11 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java > > Lines 38 (patched) > > <https://reviews.apache.org/r/72666/diff/3/?file=2235769#file2235769line38> > > > > 'bufferElementClass' can be derived from the generic, as below. With > > this, bufferElementClass argument can be eliminated. > > > > ParameterizedType genericSuperclass = (ParameterizedType) > > getClass().getGenericSuperclass(); > > Type type = > > genericSuperclass.getActualTypeArguments()[0]; > > > > if (type instanceof ParameterizedType) { > > this.bufferElementClass = (Class<T>) ((ParameterizedType) > > type).getRawType(); > > } else { > > this.bufferElementClass = (Class<T>) type; > > }
This inference mechanism works only when a concreate class is derived from the gerneric. I have done that. This leads to 2 additional classes but makes the implementation cleaner. > On July 10, 2020, 8:11 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java > > Lines 56 (patched) > > <https://reviews.apache.org/r/72666/diff/3/?file=2235769#file2235769line56> > > > > - set() => add() - to be consistent with ArrayList > > - better yet, consider collapsing both get() and set() with the > > following: > > public T getForUpdate(int idx) { > > if (this.length <= idx) { > > this.length = (idx + 1); > > > > request(this.length); > > } > > > > return buffer.get(idx); > > } I hve implemented getForUpdate that makes add or set unnecessary. > On July 10, 2020, 8:11 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java > > Lines 62 (patched) > > <https://reviews.apache.org/r/72666/diff/3/?file=2235769#file2235769line62> > > > > Calling toList() effectively clears the buffer (since the > > currentIndex/length is reset). This is not intutive. Consider adding a > > separate method, reset(), for this. Adding reset will lead to additional call in the usage. > On July 10, 2020, 8:11 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java > > Lines 77 (patched) > > <https://reviews.apache.org/r/72666/diff/3/?file=2235769#file2235769line77> > > > > It might help to defer instantiation until an entry is accessed. > > Consider handling this in get(idx): > > public T get(int i) { > > request(i + 1); > > > > T ret = buffer.get(i); > > > > if (ret == null) { > > ret = elementClass.newInstance(); > > > > buffer.set(i, ret); > > } > > > > return ret; > > } > > > > With this change, instantiateElements() will not be needed. I prefer keeping the list ready when accessed. > On July 10, 2020, 8:11 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java > > Lines 83 (patched) > > <https://reviews.apache.org/r/72666/diff/3/?file=2235769#file2235769line83> > > > > The intrepretation of 'incrementByFactor' doesn't look right. Shouldn't > > it be something like: > > > > // incrementByFactor should be a float, with value > 0 > > // incrCapacity can be initialized in constructor as well > > int incrCapacity = (int) (this.capacity * incrementByFactor) + 1.0F; > > > > int newCapacity = this.capacity; > > > > for (; newCapacity < requestedSize; newCapacity += incrCapacity); > > > > this.buffer.ensureCapacity(newCapacity); > > > > return newCapacity; incrementByFactor increments the current capacity. - Ashutosh ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/72666/#review221193 ----------------------------------------------------------- On July 13, 2020, 7:45 p.m., Ashutosh Mestry wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/72666/ > ----------------------------------------------------------- > > (Updated July 13, 2020, 7:45 p.m.) > > > Review request for atlas, Madhan Neethiraj, Nikhil Bonte, Nixon Rodrigues, > and Sarath Subramanian. > > > Bugs: ATLAS-3878 > https://issues.apache.org/jira/browse/ATLAS-3878 > > > Repository: atlas > > > Description > ------- > > **Background** > See JIRA for details. > > *Analysis* Using memory profiling tools, it was observed that large number of > notification objects were created. These stayed in memory and later were > promoted to higher generation, thereby taking even longer to be collected. > > **Approach** > Using the fixed-buffer approach to address the problem of creating large > number of small objects. > > New *FixedBufferList* This is an encapsulation over *ArrayList*. During > initial allocation, list is populated with default values. Features: > - Setting of values to these pre-allocated objects is achieved by first doing > a *get* on the element and then assigning values to it. > - *toList* fetches the sub-list from the encapsulating list. This uses the > state within the class to fetch the right length for the returning array. > > New *NamedFixedBufferList* Maintains a per-thread *FixedBufferList*. This is > necessary since the list is now part class's state. > Modified *EntityAuditListenerV2* Uses the new classes. > Modifed *EntityNotificationListener* Uses the new classes. > > **Verification** > - Using the test setup, the memory usage was observed over a period of 24 > hrs. > - Memory usage and object allocation was obvserved using memory profiler. > > > Diffs > ----- > > intg/src/main/java/org/apache/atlas/AtlasConfiguration.java 2c007ca01 > intg/src/main/java/org/apache/atlas/utils/FixedBufferList.java PRE-CREATION > intg/src/main/java/org/apache/atlas/utils/FixedBufferListAccessor.java > PRE-CREATION > intg/src/test/java/org/apache/atlas/utils/FixedBufferListAccessorTest.java > PRE-CREATION > intg/src/test/java/org/apache/atlas/utils/FixedBufferListTest.java > PRE-CREATION > > repository/src/main/java/org/apache/atlas/repository/audit/EntityAuditListenerV2.java > 79527acfa > > webapp/src/main/java/org/apache/atlas/notification/EntityNotificationListenerV2.java > a677b315c > > > Diff: https://reviews.apache.org/r/72666/diff/4/ > > > Testing > ------- > > **Unit testing** > Unit tests added for the new classes. > > **Volume testing** > Setup: > - Node: Threads 40, Core: 40, Allocated Memory: 12 GB > - Multiple Kafka queues ingesting data. > - Bulk entity creation using custom script ingesting 100M entities. > > Memory usage stayed between 0 and 5% during the 24 hr period. > > With: > - Workers: 64 > - Batch size: 50 (fewer elements in batch improve commit time and audit write > time). > - Throughput: ~1.2 M entities per hour. > > **Pre-commit** > https://builds.apache.org/view/A/view/Atlas/job/PreCommit-ATLAS-Build-Test/2035/ > > > Thanks, > > Ashutosh Mestry > >
