Azure Cosmos DB, five APIs, globally distributed.

Identifies HTTP 429 rate-limiting events, pinpointing physical partition ranges exhausting provisioned or autoscale RU/s capacity.

// Query HTTP 429 throttling and RU consumption by partition key range
CDBDataPlaneRequests
| where TimeGenerated >= ago(1h)
| summarize RequestCount = count(), TotalRUs = sum(RequestCharge)
    by StatusCode, PartitionKeyRangeId, OperationName
| where StatusCode == 429 or TotalRUs > 5000
| order by RequestCount desc;

// Inspect normalized RU consumption across physical partition ranges
AzureMetrics
| where MetricName == "NormalizedRUConsumption"
| where TimeGenerated >= ago(1h)
| summarize MaxNormalizedRU = max(Maximum) by bin(TimeGenerated, 5m), Resource;

Surfaces high-charge cross-partition fan-out queries and validates multi-master account replication and failover policies.

# Query Cosmos DB diagnostic logs for expensive cross-partition queries
az monitor log-analytics query \
  --workspace "$AZURE_LOG_ANALYTICS_WORKSPACE_ID" \
  --analytics-query "CDBQueryRuntimeStatistics | where TimeGenerated >= ago(1h) | where QueryCharge > 500 | project TimeGenerated, QueryCharge, RetrievedDocumentCount, OutputDocumentCount, ActivityId | order by QueryCharge desc | take 10"

# Inspect account failover priority and multi-region replication status
az cosmosdb show \
  --name "prod-cosmosdb-account" \
  --resource-group "production-rg" \
  --query "{locations: locations, failoverPolicies: failoverPolicies, isMultiMaster: enableMultipleWriteLocations}"