View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0006716 | SymmetricDS Pro | Improvement | public | 2025-02-05 02:24 | 2025-02-05 02:43 |
| Reporter | pbelov | Assigned To | pbelov | ||
| Priority | normal | ||||
| Status | assigned | Resolution | open | ||
| Product Version | 3.15.0 | ||||
| Target Version | 3.15.13 | ||||
| Summary | 0006716: Deadlocks on Sybase due to default table locking scheme being overly restrictive | ||||
| Description | SymmetricDS uses multiple threads to update internal and customer tables. If a Sybase database server has overly restrictive locking scheme (allpages or datapages) this could result in SymmetricDS processes issuing dead-locked queries, which hurts performance (batch must be re-tried later). Solution is to update SymmetricDS class AseDdlBuilder to create all tables with the locking scheme set to "datarows" explicitly. This will override default locking scheme set by DBA (or a lack of such setting resulting in a problematic default "allpages" scheme). | ||||
| Steps To Reproduce | Load 3 large tables. Observe at least two queries dead-locked - using the sp_lock2 built-in stored procedure. one query with column BlockedState = 'Blocked' and onether query with BlockedState='Blocking' | ||||
| Additional Information | Originally reported by Benjamin S. (and independently by Phillip M.) https://sourceforge.net/p/symmetricds/discussion/739236/thread/c6964e72ea/?limit=25 https://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.dc20021_1251/html/locking/X12029.htm | ||||
| Tags | dialect: sybase | ||||
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2025-02-05 02:24 | pbelov | New Issue | |
| 2025-02-05 02:24 | pbelov | Status | new => assigned |
| 2025-02-05 02:24 | pbelov | Assigned To | => pbelov |
| 2025-02-05 02:24 | pbelov | Tag Attached: dialect: sybase | |
| 2025-02-05 02:33 | pbelov | Description Updated | View Revisions |
| 2025-02-05 02:35 | pbelov | Steps to Reproduce Updated | View Revisions |
| 2025-02-05 02:35 | pbelov | Summary | Deadlocks on Sybase due to default table lock scheme being too optimistic => Deadlocks on Sybase due to default table lock scheme being overly restrictive |
| 2025-02-05 02:37 | pbelov | Summary | Deadlocks on Sybase due to default table lock scheme being overly restrictive => Deadlocks on Sybase due to default table locking scheme being overly restrictive |
| 2025-02-05 02:43 | pbelov | Note Added: 0002604 |