View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0005033 | SymmetricDS Pro | Bug | public | 2021-06-16 13:08 | 2021-07-13 19:48 |
| Reporter | pmarzullo | Assigned To | pmarzullo | ||
| Priority | normal | ||||
| Status | closed | Resolution | fixed | ||
| Product Version | 3.12.10 | ||||
| Target Version | 3.12.11 | Fixed in Version | 3.12.11 | ||
| Summary | 0005033: Oracle Log Miner fails to load transactions when SCN value is too old and gets stuck in loop | ||||
| Description | When a pending transaction from sym_context is attempted to be loaded, and the SCN value for the beginning of the transaction is too old, and the next SCN value minus 1 is also too old, then the log mining gets stuck in a loop that never ends. The minimum value of the pending transaction SCN values is put in as the start SCN, and the next SCN minus 1 is put in as the end SCN. If the start SCN is too old (no redo log is found for that SCN), then the recovery attempts to put in the minimum SCN value from the current redo logs. But when this minimum SCN value is greater than our starting SCN, then the start SCN value is greater than the end SCN value, causing another failure when starting log mining. In this case, where the minimum SCN value is greater than our end SCN value, then the current pending transactions are not able to be recovered. We should log the lost transactions and move on. | ||||
| Steps To Reproduce | 1. Find the current minimum SCN value from the database: SELECT "FIRST_CHANGE#" AS FIRST_SCN FROM V$LOG WHERE status = 'CURRENT' ORDER BY \"SEQUENCE#\" DESC 2. Set the sym_context value with a value less than the minimum SCN value: update sym_context set context_value = <value less than first_change#' where name='log.miner.next.id'; 3. Insert/update sym_context with an open transaction less than value just inserted into sym_context for next id: insert into sym_context (name, context_value, create_time, last_update_time) values('log.miner.open.transactions', '1-1-10',current_timestamp, current_timestamp); 4. Start up SymmetricDS with Oracle log mining. | ||||
| Tags | dialect: oracle, log miner | ||||
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2021-06-16 13:08 | pmarzullo | New Issue | |
| 2021-06-16 13:08 | pmarzullo | Status | new => assigned |
| 2021-06-16 13:08 | pmarzullo | Assigned To | => pmarzullo |
| 2021-06-16 13:08 | pmarzullo | Tag Attached: dialect: oracle | |
| 2021-06-16 13:08 | pmarzullo | Tag Attached: log-miner | |
| 2021-06-16 13:10 | pmarzullo | Status | assigned => resolved |
| 2021-06-16 13:10 | pmarzullo | Resolution | open => fixed |
| 2021-06-16 13:10 | pmarzullo | Fixed in Version | => 3.12.11 |
| 2021-06-16 13:10 | pmarzullo | Note Added: 0001956 | |
| 2021-07-13 19:48 | admin | Status | resolved => closed |
| 2022-08-09 17:57 | admin | Tag Renamed | log-miner => log miner |