/// <summary>
/// This test come from a support case where dropping an index would block forever after index sampling failed.
/// <para>
/// A fusion index has multiple <seealso cref="IndexSampler index samplers"/> that are called sequentially. If one fails, then the other will never be invoked.
/// This was a problem for <seealso cref="LuceneIndexSampler"/>. It owns a <seealso cref="org.neo4j.helpers.TaskControl"/> that it will try to release in try-finally
/// in <seealso cref="LuceneIndexSampler.sampleIndex()"/>. But it never gets here because a prior <seealso cref="IndexSampler"/> fails.
/// </para>
/// <para>
/// Because the <seealso cref="org.neo4j.helpers.TaskControl"/> was never released the lucene accessor would block forever, waiting for
/// <seealso cref="TaskCoordinator.awaitCompletion()"/>.
/// </para>
/// <para>
/// This situation was solved by making <seealso cref="IndexSampler"/> <seealso cref="System.IDisposable"/> and include it in try-with-resource together with
/// <seealso cref="IndexReader"/> that created it.
/// </para>
/// </summary>
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test(timeout = 5_000L) public void failedIndexSamplingMustNotPreventIndexDrop() throws java.io.IOException, org.neo4j.kernel.api.exceptions.index.IndexEntryConflictException
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
public virtual void FailedIndexSamplingMustNotPreventIndexDrop()
{
LuceneIndexProvider luceneProvider = luceneProvider();
MakeSureIndexHasSomeData(luceneProvider); // Otherwise no sampler will be created.
IndexProvider failingProvider = failingProvider();
FusionIndexProvider fusionProvider = CreateFusionProvider(luceneProvider, failingProvider);
using (IndexAccessor fusionAccessor = fusionProvider.GetOnlineAccessor(_storeIndexDescriptor, _samplingConfig))
{
IndexSamplingJob indexSamplingJob = CreateIndexSamplingJob(fusionAccessor);
// Call run from other thread
try
{
indexSamplingJob.run();
}
catch (Exception e)
{
assertSame(e, _sampleException);
}
// then
fusionAccessor.Drop();
// should not block forever
}
}
