Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Fixed
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10.3(EOL), 10.4(EOL), 10.5, 10.6, 10.7(EOL), 10.8(EOL), 10.9(EOL), 10.10(EOL), 10.11
Description
We have been testing Galera-MariaDB on data consistency models. We (together with the Galera contributor) found REPEATABLE READ anomalies with Galera disabled. Hence, there might be something wrong with MariaDB. We used the default REPEATABLE READ isolation in our testing.
The collected data (or histories of transaction executions):
https://gist.github.com/sciascid/aae12c130bdcfe1930601f19ce0f29d5/archive/6b214d707fdf0fb72b2505955c0e23d38717db6d.zip
The specific anomaly was shown at https://github.com/codership/galera/issues/609#issuecomment-1036096287 Also see the table attached.
Notation: w/r(key, value, client_id, txn_id); operations of a txn (denoted by a column) are listed from top down.
Anomaly: txn393 read value 3328 on key 0 (red cell, column 1) in between the reads of value 33324 on key 0 (yellow cells).
Setup: 3 server nodes and 3 client nodes. Galera Version: 26.4.9. MariaDB Version: 10.4.22.
Attachments
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Activity
| Field | Original Value | New Value |
|---|---|---|
| Description |
We have been testing Galera-MariaDB on data consistency models. We (together with the Galera contributor) found REPEATABLE READ anomalies with Galera disabled. Hence, there might be something wrong with MariaDB. We used the default REPEATABLE READ isolation in our testing.
The collected data (or histories of transaction executions): https://gist.github.com/sciascid/aae12c130bdcfe1930601f19ce0f29d5/archive/6b214d707fdf0fb72b2505955c0e23d38717db6d.zip The specific anomaly was reported at https://github.com/codership/galera/issues/609#issuecomment-1036096287 See the table. *Notation*: w/r(key, value, client_id, txn_id); operations of a txn (denoted by a column) are listed from top down. *Anomaly*: txn393 read value 3328 on key 0 (red cell, column 1) in between the reads of value 33324 on key 0 (yellow cells). *Setup*: 3 server nodes and 3 client nodes. Galera Version: 26.4.9. MariaDB Version: 10.4.22. |
We have been testing Galera-MariaDB on data consistency models. We (together with the Galera contributor) found REPEATABLE READ anomalies with Galera disabled. Hence, there might be something wrong with MariaDB. We used the default REPEATABLE READ isolation in our testing.
The collected data (or histories of transaction executions): https://gist.github.com/sciascid/aae12c130bdcfe1930601f19ce0f29d5/archive/6b214d707fdf0fb72b2505955c0e23d38717db6d.zip The specific anomaly was shown at https://github.com/codership/galera/issues/609#issuecomment-1036096287 See the table. *Notation*: w/r(key, value, client_id, txn_id); operations of a txn (denoted by a column) are listed from top down. *Anomaly*: txn393 read value 3328 on key 0 (red cell, column 1) in between the reads of value 33324 on key 0 (yellow cells). *Setup*: 3 server nodes and 3 client nodes. Galera Version: 26.4.9. MariaDB Version: 10.4.22. |
| Attachment | 153581722-b12574db-09df-4176-adba-504f532b5ea9.png [ 62313 ] |
| Description |
We have been testing Galera-MariaDB on data consistency models. We (together with the Galera contributor) found REPEATABLE READ anomalies with Galera disabled. Hence, there might be something wrong with MariaDB. We used the default REPEATABLE READ isolation in our testing.
The collected data (or histories of transaction executions): https://gist.github.com/sciascid/aae12c130bdcfe1930601f19ce0f29d5/archive/6b214d707fdf0fb72b2505955c0e23d38717db6d.zip The specific anomaly was shown at https://github.com/codership/galera/issues/609#issuecomment-1036096287 See the table. *Notation*: w/r(key, value, client_id, txn_id); operations of a txn (denoted by a column) are listed from top down. *Anomaly*: txn393 read value 3328 on key 0 (red cell, column 1) in between the reads of value 33324 on key 0 (yellow cells). *Setup*: 3 server nodes and 3 client nodes. Galera Version: 26.4.9. MariaDB Version: 10.4.22. |
We have been testing Galera-MariaDB on data consistency models. We (together with the Galera contributor) found REPEATABLE READ anomalies with Galera disabled. Hence, there might be something wrong with MariaDB. We used the default REPEATABLE READ isolation in our testing.
The collected data (or histories of transaction executions): https://gist.github.com/sciascid/aae12c130bdcfe1930601f19ce0f29d5/archive/6b214d707fdf0fb72b2505955c0e23d38717db6d.zip The specific anomaly was shown at https://github.com/codership/galera/issues/609#issuecomment-1036096287 Also see the table attached. *Notation*: w/r(key, value, client_id, txn_id); operations of a txn (denoted by a column) are listed from top down. *Anomaly*: txn393 read value 3328 on key 0 (red cell, column 1) in between the reads of value 33324 on key 0 (yellow cells). *Setup*: 3 server nodes and 3 client nodes. Galera Version: 26.4.9. MariaDB Version: 10.4.22. |
| Labels | galera isolation repeatable_read tests | galera innodb isolation repeatable_read |
| Key |
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| Project | MariaDB Foundation Internal [ 12001 ] | MariaDB Server [ 10000 ] |
| Assignee | Marko Mäkelä [ marko ] |
| Fix Version/s | 10.4 [ 22408 ] | |
| Affects Version/s | 10.4 [ 22408 ] |
| Status | Open [ 1 ] | Needs Feedback [ 10501 ] |
| Comment |
[ First of all, the Repeatable Read we mentioned here is actually Cut Isolation (lower level of Repeatable Read), i.e., given a key and a transaction, if this transaction read the key multiple times and there is no write on the key between these read operations, then the results of read should be consistent.
For the executable testing scripts, in the beginning, we were testing Causal Consistency of Galera Cluster. During the investigation, we found this repeatable read problem. To be noticed, the data reported here were generated by the Galera engineer, who managed to get the data from a single MariaDB node, with Galera replication disabled. Our original testing scripts cannot detect this Repeatable Read issue, so we created a new testing script for it. I attached our testing scripts here: https://github.com/20211202na/galera_data_generation Our testing scripts are following Jepsen’s testing methodology. Since it is black-box testing, we cannot produce the exact same results. If you want to reproduce this violation, it’s better to rerun the testing scripts with larger parameters. For example, 20 keys, 10 clients, 100 transactions per client, and 25 operations per transaction. ] |
| Status | Needs Feedback [ 10501 ] | Open [ 1 ] |
| Status | Open [ 1 ] | Needs Feedback [ 10501 ] |
| Assignee | Marko Mäkelä [ marko ] | Vladislav Lesin [ vlad.lesin ] |
| Status | Needs Feedback [ 10501 ] | Open [ 1 ] |
| Status | Open [ 1 ] | Confirmed [ 10101 ] |
| Status | Confirmed [ 10101 ] | In Progress [ 3 ] |
| Attachment | MDEV-27927-test.diff [ 65240 ] |
| Summary | REPEATABLE READ anomaly found | row_sel_try_search_shortcut_for_mysql() does not latch a page, what causes RR and RC isolation violaion |
| Summary | row_sel_try_search_shortcut_for_mysql() does not latch a page, what causes RR and RC isolation violaion | row_sel_try_search_shortcut_for_mysql() does not latch a page, violating read view isolation |
| Fix Version/s | 10.3 [ 22126 ] | |
| Fix Version/s | 10.5 [ 23123 ] | |
| Fix Version/s | 10.6 [ 24028 ] | |
| Fix Version/s | 10.7 [ 24805 ] | |
| Fix Version/s | 10.8 [ 26121 ] | |
| Fix Version/s | 10.9 [ 26905 ] | |
| Fix Version/s | 10.10 [ 27530 ] | |
| Affects Version/s | 10.3 [ 22126 ] | |
| Affects Version/s | 10.5 [ 23123 ] | |
| Affects Version/s | 10.6 [ 24028 ] | |
| Affects Version/s | 10.7 [ 24805 ] | |
| Affects Version/s | 10.8 [ 26121 ] | |
| Affects Version/s | 10.9 [ 26905 ] | |
| Affects Version/s | 10.10 [ 27530 ] | |
| Affects Version/s | 10.11 [ 27614 ] |
| Fix Version/s | 10.11 [ 27614 ] |
| Attachment | MDEV-27927.pdf [ 65416 ] |
| Component/s | Storage Engine - InnoDB [ 10129 ] | |
| Fix Version/s | 10.3.37 [ 28404 ] | |
| Fix Version/s | 10.4.27 [ 28405 ] | |
| Fix Version/s | 10.5.18 [ 28421 ] | |
| Fix Version/s | 10.6.11 [ 28441 ] | |
| Fix Version/s | 10.7.7 [ 28442 ] | |
| Fix Version/s | 10.8.6 [ 28443 ] | |
| Fix Version/s | 10.9.4 [ 28444 ] | |
| Fix Version/s | 10.10.2 [ 28410 ] | |
| Fix Version/s | 10.11.1 [ 28454 ] | |
| Fix Version/s | 10.3 [ 22126 ] | |
| Fix Version/s | 10.4 [ 22408 ] | |
| Fix Version/s | 10.5 [ 23123 ] | |
| Fix Version/s | 10.6 [ 24028 ] | |
| Fix Version/s | 10.7 [ 24805 ] | |
| Fix Version/s | 10.8 [ 26121 ] | |
| Fix Version/s | 10.9 [ 26905 ] | |
| Fix Version/s | 10.10 [ 27530 ] | |
| Fix Version/s | 10.11 [ 27614 ] | |
| Resolution | Fixed [ 1 ] | |
| Status | In Progress [ 3 ] | Closed [ 6 ] |
| Remote Link | This issue links to "Page (MariaDB Confluence)" [ 35624 ] |
| Remote Link | This issue links to "Page (MariaDB Confluence)" [ 35633 ] |
| Remote Link | This issue links to "Page (MariaDB Confluence)" [ 35624 ] |
| Zendesk Related Tickets | 202352 201658 | |
| Zendesk active tickets | 201658 |