Hi,

We're using Umbraco 8.2.2 for a large site. Everytime we restart the applicationpool we have to reindex all Examine indexes because we're using examine to find the latest newsitems that are meeting some conditions.

If we dont index manualy after starting the site, this content is not showing up. Sometimes it looks like the indexes get corrupt with causes high CPU usage. If we reindex again, the performance gets back to normal.

Often (a few times a day) we get these type of errors:

[Error] Error indexing queue items
System.ArgumentNullException: Value cannot be null.
Parameter name: key
   at System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
   at System.Collections.Generic.Dictionary`2.Remove(TKey key)
   at Umbraco.Examine.ValueSetValidator.Validate(ValueSet valueSet) in C:\Umbraco-CMS-8-8.2\src\Umbraco.Examine\ValueSetValidator.cs:line 85
   at Examine.Providers.BaseIndexProvider.<IndexItems>b__12_0(ValueSet x) in C:\projects\examine-qvx04\src\Examine\Providers\BaseIndexProvider.cs:line 76
   at System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()
   at Examine.LuceneEngine.Providers.LuceneIndex.ForceProcessQueueItems(Boolean block) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 879

and these:

[Error] Error indexing queue items
System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Collections.Generic.Dictionary`2.CopyTo(KeyValuePair`2[] array, Int32 index)
   at Examine.LuceneEngine.Providers.LuceneIndex.CopyDictionary(IDictionary`2 d) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 654
   at Examine.LuceneEngine.Providers.LuceneIndex.AddDocument(Document doc, ValueSet valueSet, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 666
   at Examine.LuceneEngine.Providers.LuceneIndex.ProcessIndexQueueItem(IndexOperation op, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 1201
   at Examine.LuceneEngine.Providers.LuceneIndex.ProcessQueueItem(IndexOperation item, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 1020
   at Examine.LuceneEngine.Providers.LuceneIndex.ForceProcessQueueItems(Boolean block) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 879
2020-03-04 20:10:33.635 +01:00 [Error] Error indexing queue items
System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Collections.Generic.Dictionary`2.CopyTo(KeyValuePair`2[] array, Int32 index)
   at Examine.LuceneEngine.Providers.LuceneIndex.CopyDictionary(IDictionary`2 d) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 654
   at Examine.LuceneEngine.Providers.LuceneIndex.AddDocument(Document doc, ValueSet valueSet, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 666
   at Examine.LuceneEngine.Providers.LuceneIndex.ProcessIndexQueueItem(IndexOperation op, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 1201
   at Examine.LuceneEngine.Providers.LuceneIndex.ProcessQueueItem(IndexOperation item, IndexWriter writer) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 1020
   at Examine.LuceneEngine.Providers.LuceneIndex.ForceProcessQueueItems(Boolean block) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneIndex.cs:line 879

Unfortunately, the index name is not mentioned in the error message.

Is there a way to find out which nodes might cause these indexing problems?

Best regards,

iNETZO