Unable to cast object of type 'System.Int32' to type 'System.Collections.ArrayList'."

Question

We have a replicated cache with 2 nodes, from time to time, we received this error and we aren't able to resolve: "Unable to cast object of type 'System.Int32' to type 'System.Collections.ArrayList'."

The stacktrace:

at Alachisoft.NCache.Web.Command.CommandResponse.ParseResponse()
at Alachisoft.NCache.Web.Caching.RemoteCache.Add(String key, Object value, CacheDependency dependency, CacheSyncDependency syncDependency, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, Int16 removeCallback, Int16 updateCallback, Int16 dsItemAddedCallback, Boolean isResyncExpiredItems, String group, String subGroup, Hashtable queryInfo, BitSet flagMap, String providerName, String resyncProviderName, EventDataFilter updateCallbackFilter, EventDataFilter removeCallabackFilter, Int64 size, String clientId)
   at Alachisoft.NCache.Web.Caching.Cache.AddOperation(String key, Object value, CacheDependency dependency, CacheSyncDependency syncDependency, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, DSWriteOption dsWriteOption, CacheItemRemovedCallback onRemoveCallback, CacheItemUpdatedCallback onUpdateCallback, DataSourceItemsAddedCallback onDataSourceItemAdded, Boolean isResyncExpiredItems, String group, String subGroup, Tag[] tags, String providerName, String resyncProviderName, NamedTagsDictionary namedTags, CacheDataNotificationCallback cacheItemUdpatedCallback, CacheDataNotificationCallback cacheItemRemovedCallaback, EventDataFilter itemUpdateDataFilter, EventDataFilter itemRemovedDataFilter, Int64&amp; size, Boolean allowQueryTags, String clientId, Int16 updateCallbackID, Int16 removeCallbackID, Int16 dsItemAddedCallbackID)
   at Alachisoft.NCache.Web.Caching.Cache.Add(String key, CacheItem item, DSWriteOption dsWriteOption, DataSourceItemsAddedCallback onDataSourceItemAdded)
   at Alachisoft.NCache.Web.Caching.Cache.Add(String key, CacheItem item)

In the log files we see:

...received response for request 118849, sender=<IP_Server_1>:7800, val=System.Byte[]
...received response for request 118849, sender=<IP_Server_2>:7800, val=Alachisoft.NCache.Common.DataStructures.Clustered.ClusteredArrayList

How can we resolve this problem?

score 0 · Answer 1 · answered Nov 13 '18 at 06:13

The casting exception that you are getting is rather strange. This usually thrown on Cache get calls where you may be using an invalid cast. However, in this particular case it is on adding item to the cache which makes me believe this is on server side. Will need to review this - can you share some more details on this.

Please share complete application code snippet along with the flow on _cache.Add API within your code. Also share NCache version and edition information in order to review this in detail. You can run the "verifylicense.exe" tool (located at "C:\Program Files\NCache\bin\tools\verifylicense.exe") to check the current NCache version.

I think you should contact NCache support - support@alachisoft.com - their support is excellent - they should be able to expedite this for you.

Unable to cast object of type 'System.Int32' to type 'System.Collections.ArrayList'."

1 Answers1