SSIS中SYNCHRONIZED同步参数的潜在问题咨询

Great question—even if your synchronized SSIS executions are running smoothly right now, there are a few key potential pitfalls to keep an eye on:

• Blocking of the Calling Process
  When you set SYNCHRONIZED = 1, the process that triggers the SSIS package (whether it's a SQL Agent job step, an SSMS query, or an application) will hang in a "waiting" state until the package completes entirely. If your package runs for a long time (hours, for example), this calling process will be tied up—SQL Agent jobs will show as "Running" indefinitely, application threads will be blocked, and you won't be able to reuse that session for other tasks until the package finishes.

• Increased Resource Contention
  Synchronized executions hold onto resources like database connections, memory, and SSISDB locks for the entire duration of the package run. If you have multiple synchronized executions running at the same time, this can lead to heightened resource competition: SSISDB might experience lock waits, server CPU/memory usage could spike, and other critical processes on your server might be impacted.

• Fragile Error Handling & Execution State Risks
  If the calling process is interrupted unexpectedly (e.g., network drop, SSMS window closed, application crash), the SSIS package execution might terminate abruptly or enter an inconsistent state. Unlike asynchronous execution (where the package runs independently in the background), synchronized mode ties the package's fate directly to the calling session. Additionally, you won't get visibility into intermediate step progress—you'll only know the final result once everything is done.

• Timeout Mismatches
  Most calling environments (like SQL Agent command timeouts, ADO.NET connection timeouts) have default limits on how long they'll wait for a process to complete. If your SSIS package runs longer than this timeout value, the calling process will throw a timeout error—but the package might still continue running in the background. This creates a mismatch where your calling system thinks the execution failed, but the SSIS job is still active, leading to confusion and potential data inconsistencies.

• Scalability Bottlenecks
  Synchronized execution is inherently serial if you're triggering packages from a single process. If you need to run multiple SSIS packages in parallel (e.g., for batch processing across multiple datasets), synchronized mode forces you to either wait for one to finish before starting the next or implement complex multi-threading logic. Asynchronous execution, by contrast, lets you fire off multiple package executions quickly without waiting for each to complete.

Quick Note for Your Current Setup #

If you haven't hit any issues yet, it's likely your use case aligns well with synchronized execution (e.g., short-running packages, business flows that require immediate execution results). Just keep these pitfalls in mind if your package runtime grows, or if you need to scale up your SSIS workloads.

内容的提问来源于stack exchange，提问作者vishnu k