Queries for the FailedIngestion table

Failed ingestions by errors

How many ingestion failures accrued (by ErrorCode).

FailedIngestion 
| summarize count() by ErrorCode

Failed ingestions timechart

How many ingestion failures accrued (timechart).

FailedIngestion 
| summarize count() by bin(TimeGenerated, 5m) 
| render timechart 

Failed Ingestions

How many ingestion failures accrued (by cluster, database, table, ErrorCode, status).

FailedIngestion 
| parse _ResourceId with * "providers/microsoft.kusto/clusters/" cluster_name // Get the cluster name from the ResourceId string
| summarize count() by bin(TimeGenerated, 1h), cluster_name, Database, Table, ErrorCode, FailureStatus