Setting Thresholds and Warnings in Replication Monitor
Microsoft SQL Server Replication Monitor displays status information for publications and subscriptions (for a complete list of status values, see Viewing Publication and Subscription Status in Replication Monitor). By default, Replication Monitor displays warnings only for uninitialized subscriptions, but you can enable warnings for other conditions. It is recommended that you enable warnings for your topology, so that you are informed about status and performance in a timely manner.
When you enable a warning, you specify a threshold. When that threshold is met or exceeded, a warning is displayed (unless an issue with a higher priority needs to be displayed). In addition to displaying a warning in Replication Monitor, reaching a threshold can also trigger an alert. You can enable warnings for the following conditions:
Imminent subscription expiration
This applies to all types of replication. If the specified threshold is met or exceeded, the subscription status is displayed as Expiring soon/Expired.
Exceeding the specified latency (the amount of time that elapses between a transaction being committed at the Publisher and the corresponding transaction being committed at the Subscriber).
This applies to transactional replication. If the specified threshold is met or exceeded, the subscription status is displayed as Performance critical.
Exceeding the specified synchronization time.
This applies to merge replication. If the specified threshold is met or exceeded, the status is displayed as Long-running merge. You can specify different thresholds for dialup and Local Area Network (LAN) connections.
Falling short of processing the specified number of rows in a given amount of time.
This applies to merge replication. If the specified threshold is met or exceeded, the status is displayed as Performance critical. You can specify different thresholds for dialup and LAN connections.
For more information on the warnings Performance critical and Long-running merge, see Monitoring Performance with Replication Monitor.
To set thresholds and warnings
Replication Monitor: How to: Set Thresholds and Warnings for a Transactional Publication (Replication Monitor)
Replication Monitor: How to: Set Thresholds and Warnings for a Merge Publication (Replication Monitor)
Replication Monitor: How to: Set Thresholds and Warnings for a Snapshot Publication (Replication Monitor)