Troubleshooting
Problem
Exchange On-Premises archival operations may experience lower throughput or increased processing time in environments handling a high volume of archival requests. In ICC cluster deployments, these workloads can impact overall system responsiveness and processing efficiency.
Symptom
Customers may observe one or more of the following:
- Slower Exchange On-Premises archival processing.
- Reduced archival throughput during periods of high workload.
- Uneven load distribution in Cluster environments.
- Reduced system responsiveness in high-volume or clustered environments.
Cause
In high-volume Exchange On-Premises deployments, the default configuration may not fully utilize the available system resources for maximum archival throughput.
IBM Content Collector FP17 introduces optional environment variables that enable performance optimizations for Exchange On-Premises archival operations. These settings optimize processing behavior to improve throughput and overall performance.
Environment
Product: IBM Content Collector
Version: 4.0.1.17
Operating System: Windows Server 2019, Windows Server 2022, Windows Server 2025
Diagnosing The Problem
Consider applying the performance optimization settings described in this technote if one or more of the following conditions are observed:
- Exchange On-Premises archival operations take longer than expected to complete.
- Archival throughput decreases during periods of high activity.
- Workloads are not evenly distributed across IBM Content Collector cluster nodes.
- Some cluster nodes appear to process significantly more archival requests than others.
- System responsiveness decreases while large archival jobs are running.
- Performance does not improve after adding additional cluster resources.
Resolving The Problem
IBM Content Collector 4.0.1 Fix Pack 17 introduces optional environment variables that can help optimize Exchange On-Premises archival processing. Depending on workload characteristics and system configuration, these settings may help improve throughput, workload distribution, and overall processing efficiency, particularly in high-volume or clustered deployments.
To apply these optimizations:
- Stop all the ICC services in the ICC server.
- Configure the required system environment variables on the IBM Content Collector server.
- Assign the recommended value for each environment variable.
- Restart the IBM Content Collector services for the changes to take effect.
- Monitor archival throughput, processing times, and workload distribution to determine whether the changes provide benefits in your environment.
Environment Variables:
IBM_HA_DISABLE_PRIMARY_CONSTRAINTS = 1
Purpose
Allows database services to remain available during certain cluster communication issues.
Benefits
- Improves service availability during failover events
- Helps reduce interruptions caused by temporary cluster connectivity issues
- Supports continued processing during maintenance or recovery activities
AFU_BLACK_LIST_BATCH_FLOW = true
Purpose
Enables batch processing for transmitting blacklist information from the Task Routing connector to the monitoring service.
Benefits
- Sends entries in batches instead of individual network requests.
- Improves efficiency when handling large numbers of blacklist entries.
AFU_ASYNC_LOGGING = true
Purpose
Enables asynchronous logging by moving log-writing operations to a dedicated background thread.
Benefits
- Reduces disk I/O delays.
- Improves application responsiveness.
- Reduce the impact of logging on system performance.
IBM_CTMS_COLLECTOR_THROTTLE_RATE = 20
Purpose
Limits the maximum number of collector submissions processed per second.
Benefits
- Restricts processing to the configured rate.
- Prevents services from becoming overloaded.
- Helps maintain stable system performance.
IBM_CTMS_COLLECTOR_ASYNC_FUNNEL = true
Purpose
Enables asynchronous collector processing using multiple worker threads and internal processing queues.
Benefits
- Creates dedicated processing queues.
- Uses multiple worker thread pools for parallel execution.
- Routes collector submissions through an asynchronous processing pipeline.
- Distributes workload more efficiently across available resources.
IBM_CTMS_MAPI_TELEMETRY_REPORT = 1
Purpose
Enables telemetry collection and periodic reporting for MAPI operations.
Benefits
- Collects timing statistics for supported MAPI operations. The statistics can be viewed in MAPI logs.
- Provides visibility into MAPI performance.
- Helps identify MAPI operations bottlenecks.
Note
These environment variables are optional and are disabled by default. If they are not configured, IBM Content Collector continues to operate using its default processing behavior. The impact of these settings varies depending on workload characteristics, deployment topology, and available system resources. IBM recommends monitoring system performance before and after implementation to assess their effectiveness in your environment.
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Document Information
Modified date:
25 June 2026
UID
ibm17277888