{ Make this readable }

Friday, April 13, 2007

Finally!! StreamCruncher 1.12 is ready and it's no longer a Beta version. This is the Release Candidate.

(Also, performance test results - read further. Hint: 8,000 TPS !! on 1.6 GHz Laptop)

I found the time to review some parts of the Kernel code. It turned out that there were small things here and there that needed fixing. Since the Kernel is heavily multi-threaded, it was important that locking be reduced. As a result, the CAS (Compare and Set) operations (Java 1.5+) are used in many places. This is much faster than actually waiting on a lock and then realising that the logic in the protected section does not have to be executed anyway.

After fixing these issues, I modified the "TimeWindowFPerfTest" class to capture more metrics. Apart from just calculating the Average Latency added to each Event by the Kernel in a Straight/Simple processing case, this Test now calculates the average total time it takes to insert rows into the Database and for the Kernel to publish them.

The Test was already described before. This time, with the bug fixes, there were no Index-violation exceptions. So, on my Laptop running Windows XP Home with 1 GB RAM and a single 1.6Ghz Intel Centrino Processor, I ran the "TimeWindowFPerfTest" performance test using the Sun JDK 1.6 and StreamCruncher 1.12 with H2 Database.

I redirected the verbose Console output to a log file and thereby eliminated the otherwise excessive overhead added by the Console logging. This way, I also have proof of all the Tests that were performed.

The Test uses a Thread to generate and pump 'X' events in one shot without pausing. A Query with Time based Partition is defined on this Stream. The Window size is 5 seconds. A "$row_status is new" clause is used to output only the new Events that arrive at the Window and not the ones that exit the Window when their 5 seconds are over. This way, an accurate measurement of how much overhead the Kernel is imposing can be calculated. The total time taken for the entire batch to be inserted and for it to be pumped out of the Kernel can also be calculated. This can then be used to calculate the Transactions per second - the most important metric.

The Test pumps these 'X' events and then waits for some time that is sufficient for the Events to clear the area and then pumps the same number again...and again..At the end of the Test, the results are retrieved, verified and then the Averages are calculated.

Ok, here it comes..Keep in mind that this is a single CPU and the Event "pumper" and the Kernel are running in parallel. The H2 Database (current version) is completely single-Threaded - and so there's no concurrency at all, even though StreamCruncher supports concurrent operations.

I ran 3 rounds for each configuration and here are the results:

Set 1 (4000 Events per Batch):

Set 1 - Round 1
Total events published: 36000. Each batch was of size:4000. Avg time to publish each event (Latency in Msecs): 224.0
Avg time (in Msecs) to insert 4000 Events into the DB: 418.0
Avg time (in Msecs) to process 4000 Events by the Kernel: 376.0
Avg time (in Msecs) for the insertion of first Event in the batch of 4000 Events into DB to publication of last Event in batch by Kernel: 598.0

Set 1 - Round 2
Total events published: 36000. Each batch was of size:4000. Avg time to publish each event (Latency in Msecs): 199.0
Avg time (in Msecs) to insert 4000 Events into the DB: 428.0
Avg time (in Msecs) to process 4000 Events by the Kernel: 397.0
Avg time (in Msecs) for the insertion of first Event in the batch of 4000 Events into DB to publication of last Event in batch by Kernel: 600.0

Set 1 - Round 3
Total events published: 36000. Each batch was of size:4000. Avg time to publish each event (Latency in Msecs): 261.0
Avg time (in Msecs) to insert 4000 Events into the DB: 387.0
Avg time (in Msecs) to process 4000 Events by the Kernel: 336.0
Avg time (in Msecs) for the insertion of first Event in the batch of 4000 Events into DB to publication of last Event in batch by Kernel: 591.0

Set 2 (8000 Events per Batch):

Set 2 - Round 1
Total events published: 64000. Each batch was of size:8000. Avg time to publish each event (Latency in Msecs): 378.0
Avg time (in Msecs) to insert 8000 Events into the DB: 603.0
Avg time (in Msecs) to process 8000 Events by the Kernel: 699.0
Avg time (in Msecs) for the insertion of first Event in the batch of 8000 Events into DB to publication of last Event in batch by Kernel: 1044.0

Set 2 - Round 2
Total events published: 64000. Each batch was of size:8000. Avg time to publish each event (Latency in Msecs): 457.0
Avg time (in Msecs) to insert 8000 Events into the DB: 533.0
Avg time (in Msecs) to process 8000 Events by the Kernel: 666.0
Avg time (in Msecs) for the insertion of first Event in the batch of 8000 Events into DB to publication of last Event in batch by Kernel: 1013.0

Set 2 - Round 3
Total events published: 64000. Each batch was of size:8000. Avg time to publish each event (Latency in Msecs): 392.0
Avg time (in Msecs) to insert 8000 Events into the DB: 593.0
Avg time (in Msecs) to process 8000 Events by the Kernel: 839.0
Avg time (in Msecs) for the insertion of first Event in the batch of 8000 Events into DB to publication of last Event in batch by Kernel: 1064.0

Set 3 (10,000 Events per Batch):

Set 3 - Round 1
Total events published: 70000. Each batch was of size:10000. Avg time to publish each event (Latency in Msecs): 491.0
Avg time (in Msecs) to insert 10000 Events into the DB: 705.0
Avg time (in Msecs) to process 10000 Events by the Kernel: 783.0
Avg time (in Msecs) for the insertion of first Event in the batch of 10000 Events into DB to publication of last Event in batch by Kernel: 1220.0

Set 3 - Round 2
Total events published: 70000. Each batch was of size:10000. Avg time to publish each event (Latency in Msecs): 518.0
Avg time (in Msecs) to insert 10000 Events into the DB: 689.0
Avg time (in Msecs) to process 10000 Events by the Kernel: 845.0
Avg time (in Msecs) for the insertion of first Event in the batch of 10000 Events into DB to publication of last Event in batch by Kernel: 1198.0

Set 3 - Round 3
Total events published: 70000. Each batch was of size:10000. Avg time to publish each event (Latency in Msecs): 513.0
Avg time (in Msecs) to insert 10000 Events into the DB: 647.0
Avg time (in Msecs) to process 10000 Events by the Kernel: 743.0
Avg time (in Msecs) for the insertion of first Event in the batch of 10000 Events into DB to publication of last Event in batch by Kernel: 1151.0

While the Tests were running, I kept noticing that the CPU even for the 10K Set was not rising above ~15% and that for just 1 second periods. Which is quite puzzling. It might be because the Producer and the Consumer Threads are not really running in parallel because the one common resource - the Database is always locked by one of these 2 (sets of) Threads. I was expecting the CPU to peak and the Tests to crumble at the 10K Set. But it didn't, which is a very good sign.

This means that StreamCruncher can do 8000 Transactions Per Second (Straight/Simple Processing) on a very ordinary setup and perform exponentially better on better hardware (more Cores and/or CPUs) and commercial Databases. This, combined with Horizontal Partitioning of the Stream data (using the Pre-Filters and multiple Queries to split the Events and process in parallel) should produce fantastic performance.

The test results/logs can be downloaded from here.

1 comments:

Jaffe said...
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