Leve.Iteration @TearDown method called one too many times

[Alex Averbuch]

Hmmm...
After trying other approaches and then returning to the one described in my
original email everything seems to work fine.
Unless the problem resurfaces please consider this as user error, I
probably did something foolish.

On Mon, Jul 25, 2016 at 3:29 PM, Alex Averbuch <
alex.averbuch at neotechnology.com> wrote:

> FYI, I'm using:
>
>         <dependency>
>             <groupId>org.openjdk.jmh</groupId>
>             <artifactId>jmh-core</artifactId>
>             <version>1.1.3</version>
>         </dependency>
>
>
> On Mon, Jul 25, 2016 at 3:27 PM, Alex Averbuch <
> alex.averbuch at neotechnology.com> wrote:
>
>> Hi,
>> I have a benchmark for measuring database index creation.
>>
>> Summary:
>>   * It is an expensive operation (5+ seconds per invocation), so
>> Mode.SingleShotTime is used
>>   * The database runs 5 warmup iterations & 5 measurement iterations
>>   * Each iteration must create an index from scratch, so the index must
>> be dropped/deleted between iterations
>>   * To delete the index after each iteration a Level.Iteration @TearDown
>> method is used. Inside this method the index is dropped
>>
>> Problem:
>>   * It appears as though the Level.Iteration @TearDown method is being
>> called 1 more time than the @Benchmark method
>>   * This causes the database (and benchmark) to crash, because the
>> database tries to delete an index that does not exist
>>
>> When executing the benchmark code at the bottom of this email, the
>> following is written to console:
>>
>> # Run progress: 0.00% complete, ETA 00:00:00
>> # Fork: 1 of 1
>> # Warmup Iteration   1:
>> CREATE
>> DROP
>> # Warmup Iteration   2:
>> CREATE
>> DROP
>> # Warmup Iteration   3:
>> CREATE
>> DROP
>> # Warmup Iteration   4:
>> CREATE
>> DROP
>> # Warmup Iteration   5:
>> CREATE
>> DROP
>> Iteration   1:
>> CREATE
>> DROP
>> Iteration   2:
>> CREATE
>> DROP
>> Iteration   3:
>> CREATE
>> DROP
>> Iteration   4:
>> CREATE
>> DROP
>> Iteration   5:
>> CREATE
>> DROP
>> DROP                                   <--------- NOTICE THIS ADDITIONAL
>> "DROP"
>>
>>
>>
>> Does this (extra DROP) make sense?
>> Is there any way to prevent it from happening?
>> Thanks in advance!
>>
>>
>> @State( Scope.Benchmark )
>> public class CreateIndex
>> {
>>     protected Database db;
>>
>>     @Setup
>>     public void setUp()
>>     {
>>         db = new Database();
>>         // populate db
>>     }
>>
>>     @TearDown
>>     public void tearDown()
>>     {
>>         db.shutdown();
>>     }
>>
>>     @TearDown( Level.Iteration )
>>     public void dropIndex()
>>     {
>>         System.out.println("DROP");
>>         try ( Transaction tx = db.beginTx() )
>>         {
>>             // drop index
>>             tx.success();
>>         }
>>     }
>>
>>     @Benchmark
>>     @BenchmarkMode( Mode.SingleShotTime )
>>     public void createIndex()
>>     {
>>         System.out.println("CREATE");
>>         try ( Transaction tx = db.beginTx() )
>>         {
>>             // create index
>>             tx.success();
>>         }
>>     }
>> }
>>
>
>