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Posted to dev@ranger.apache.org by "Xuze Yang (Jira)" <ji...@apache.org> on 2022/03/24 06:26:00 UTC
[jira] [Updated] (RANGER-3681) Ranger Database deadlock when createPolicy is running parallel
[ https://issues.apache.org/jira/browse/RANGER-3681?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Xuze Yang updated RANGER-3681:
------------------------------
Description:
h1. Error
ranger-log：
{noformat}
2022-03-21 20:14:29,685 [http-bio-6080-exec-13] ERROR org.apache.ranger.rest.ServiceREST (ServiceREST.java:1709) - createPolicy(RangerPolicy={id={null} guid={null} isEnabled={true} createdBy={null} updatedBy={null} createTime={null} updateTime={null} version={1} service={default-Hive} name={dcp-desensitize_a162c40cdc0140b1848b98415575be6c-1647864869626} policyType={0} policyPriority={0} description={} resourceSignature={4f15e3de95c81650ad869cb93a8c47a132bbec54bdf5de8c01f5075c19754cd7} isAuditEnabled={true} serviceType={null} resources={database={RangerPolicyResource={values={dcp } isExcludes={false} isRecursive={false} }} column={RangerPolicyResource={values={* } isExcludes={false} isRecursive={false} }} table={RangerPolicyResource={values={desensitize_a162c40cdc0140b1848b98415575be6c } isExcludes={false} isRecursive={false} }} } policyLabels={Consoler } policyConditions={} policyItems={RangerPolicyItem={accessTypes={RangerPolicyItemAccess={type={all} isAllowed={true} }} users={tangbiao2 } groups={} roles={} conditions={} delegateAdmin={false} }} denyPolicyItems={} allowExceptions={} denyExceptions={} dataMaskPolicyItems={} rowFilterPolicyItems={} options={} validitySchedules={, zoneName=null, isDenyAllElse={false} }}) failed
javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
Error Code: 1213
Call: INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (?, ?, ?, ?, ?, ?, ?)
bind => [7 parameters bound]
Query: ValueReadQuery(name="x_policy_ref_resource_SEQ" sql="SELECT LAST_INSERT_ID()")
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:868)
at sun.reflect.GeneratedMethodAccessor98.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:301)
at com.sun.proxy.$Proxy30.flush(Unknown Source)
at org.apache.ranger.common.db.BaseDao.batchCreate(BaseDao.java:102)
...{noformat}
mysql-deadlock：
{noformat}
------------------------
LATEST DETECTED DEADLOCK
------------------------
2022-03-21 09:47:22 0x7ff3a4859700
*** (1) TRANSACTION:
TRANSACTION 7036760, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
MySQL thread id 27293, OS thread handle 140684415063808, query id 383930 192.168.0.76 DHCloudBG update
INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13921, 5, 'database', '2022-03-20 12:47:22.681', 1)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036760 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** (2) TRANSACTION:
TRANSACTION 7036759, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
MySQL thread id 27295, OS thread handle 140684413998848, query id 383932 192.168.0.76 DHCloudBG update
INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13920, 5, 'database', '2022-03-20 12:47:22.682', 1)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** WE ROLL BACK TRANSACTION (2){noformat}
h1. Descrition
In our production enviroment, we may create ranger hive policy in parallel. In this case it will occasionally report deadlock errors. I turned on the general_log in mysql, and captured the sql when the deadlock exception occurred, as shown below (some sql was simplified, and only the sql that caused the deadlock was kept):
{noformat}
2022-03-21T20:16:26.776033+08:00 239903 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032)
2022-03-21T20:16:26.776463+08:00 239902 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033)
2022-03-21T20:16:26.784333+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1)
2022-03-21T20:16:26.785484+08:00 239902 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1)
2022-03-21T20:16:26.787844+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 8, 'column', '2022-03-20 23:16:26.786', 1)
2022-03-21T20:16:26.788728+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 6, 'table', '2022-03-20 23:16:26.787', 1)
2022-03-21T20:16:26.810405+08:00 239902 Query rollback
2022-03-21T20:16:26.810781+08:00 239902 Query SET autocommit=1
2022-03-21T20:16:26.831309+08:00 239903 Query commit{noformat}
I exported the data in the x_policy_ref_resource table using mysqldump and simulated it in the local environment and found that there is a deadlock when the sql of the two transactions is executed as following order：
||transation1||transation2||
|begin|begin|
|DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032);| |
| |DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033);|
|INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1);| |
| |INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1);|
# When transaction1 and transaction2 execute delete sql, they will both obtain gap lock, because gap locks are compatible.
# Then transaction 1 executes insert sql, it will try to acquire the insert intention lock, which conflicts with the gap lock held by transaction 2, and enters the lock waiting state.
# Finally, transaction2 executes insert sql, and also tries to acquire the insert intention lock, which conflicts with the gap lock held by transaction1. At this point, it is caught in a cycle where transaction1 waits for transaction 2 to release the gap lock, and transaction2 waits for transaction1 to release the gap lock. Two transactions waiting for each other to release locks eventually lead to a deadlock.
was:
h1. Error
ranger-log：
{noformat}
2022-03-21 20:14:29,685 [http-bio-6080-exec-13] ERROR org.apache.ranger.rest.ServiceREST (ServiceREST.java:1709) - createPolicy(RangerPolicy={id={null} guid={null} isEnabled={true} createdBy={null} updatedBy={null} createTime={null} updateTime={null} version={1} service={default-Hive} name={dcp-desensitize_a162c40cdc0140b1848b98415575be6c-1647864869626} policyType={0} policyPriority={0} description={} resourceSignature={4f15e3de95c81650ad869cb93a8c47a132bbec54bdf5de8c01f5075c19754cd7} isAuditEnabled={true} serviceType={null} resources={database={RangerPolicyResource={values={dcp } isExcludes={false} isRecursive={false} }} column={RangerPolicyResource={values={* } isExcludes={false} isRecursive={false} }} table={RangerPolicyResource={values={desensitize_a162c40cdc0140b1848b98415575be6c } isExcludes={false} isRecursive={false} }} } policyLabels={Consoler } policyConditions={} policyItems={RangerPolicyItem={accessTypes={RangerPolicyItemAccess={type={all} isAllowed={true} }} users={tangbiao2 } groups={} roles={} conditions={} delegateAdmin={false} }} denyPolicyItems={} allowExceptions={} denyExceptions={} dataMaskPolicyItems={} rowFilterPolicyItems={} options={} validitySchedules={, zoneName=null, isDenyAllElse={false} }}) failed
javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
Error Code: 1213
Call: INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (?, ?, ?, ?, ?, ?, ?)
bind => [7 parameters bound]
Query: ValueReadQuery(name="x_policy_ref_resource_SEQ" sql="SELECT LAST_INSERT_ID()")
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:868)
at sun.reflect.GeneratedMethodAccessor98.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:301)
at com.sun.proxy.$Proxy30.flush(Unknown Source)
at org.apache.ranger.common.db.BaseDao.batchCreate(BaseDao.java:102)
...{noformat}
mysql-deadlock：
{noformat}
------------------------
LATEST DETECTED DEADLOCK
------------------------
2022-03-21 09:47:22 0x7ff3a4859700
*** (1) TRANSACTION:
TRANSACTION 7036760, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
MySQL thread id 27293, OS thread handle 140684415063808, query id 383930 192.168.0.76 DHCloudBG update
INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13921, 5, 'database', '2022-03-20 12:47:22.681', 1)
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036760 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** (2) TRANSACTION:
TRANSACTION 7036759, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
MySQL thread id 27295, OS thread handle 140684413998848, query id 383932 192.168.0.76 DHCloudBG update
INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13920, 5, 'database', '2022-03-20 12:47:22.682', 1)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;*** WE ROLL BACK TRANSACTION (2){noformat}
h1. Descrition
In our production enviroment, we may create ranger hive policy in parallel. In this case it will occasionally report deadlock errors. I turned on the general_log in mysql, and captured the sql when the deadlock exception occurred, as shown below (some sql was simplified, and only the sql that caused the deadlock was kept):
{noformat}
2022-03-21T20:16:26.776033+08:00 239903 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032)
2022-03-21T20:16:26.776463+08:00 239902 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033)
2022-03-21T20:16:26.784333+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1)
2022-03-21T20:16:26.785484+08:00 239902 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1)
2022-03-21T20:16:26.787844+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 8, 'column', '2022-03-20 23:16:26.786', 1)
2022-03-21T20:16:26.788728+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 6, 'table', '2022-03-20 23:16:26.787', 1)
2022-03-21T20:16:26.810405+08:00 239902 Query rollback
2022-03-21T20:16:26.810781+08:00 239902 Query SET autocommit=1
2022-03-21T20:16:26.831309+08:00 239903 Query commit{noformat}
I exported the data in the x_policy_ref_resource table using mysqldump and simulated it in the local environment and found that there is a deadlock when the sql of the two transactions is executed as following order：
||transation1||transation2||
|begin|begin|
|DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032);| |
| |DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033);|
|INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1);| |
| |INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1);|
# When transaction1 and transaction2 execute delete sql, they will both obtain gap lock, because gap locks are compatible
# Then transaction 1 executes insert sql, it will try to acquire the insert intention lock, which conflicts with the gap lock held by transaction 2, and enters the lock waiting state.
# Finally, transaction2 executes insert sql, and also tries to acquire the insert intention lock, which conflicts with the gap lock held by transaction1. At this point, it is caught in a cycle where transaction1 waits for transaction 2 to release the gap lock, and transaction2 waits for transaction1 to release the gap lock. Two transactions waiting for each other to release locks eventually lead to a deadlock.
> Ranger Database deadlock when createPolicy is running parallel
> --------------------------------------------------------------
>
> Key: RANGER-3681
> URL: https://issues.apache.org/jira/browse/RANGER-3681
> Project: Ranger
> Issue Type: Bug
> Components: admin
> Affects Versions: 2.1.0
> Environment: ranger-version: 2.1.0
> mysql-verison: 5.7.34-log
> mysql-engine: InnoDB
> mysql-isolation-level: REPEATABLE-READ
> Reporter: Xuze Yang
> Assignee: Xuze Yang
> Priority: Major
>
> h1. Error
> ranger-log：
> {noformat}
> 2022-03-21 20:14:29,685 [http-bio-6080-exec-13] ERROR org.apache.ranger.rest.ServiceREST (ServiceREST.java:1709) - createPolicy(RangerPolicy={id={null} guid={null} isEnabled={true} createdBy={null} updatedBy={null} createTime={null} updateTime={null} version={1} service={default-Hive} name={dcp-desensitize_a162c40cdc0140b1848b98415575be6c-1647864869626} policyType={0} policyPriority={0} description={} resourceSignature={4f15e3de95c81650ad869cb93a8c47a132bbec54bdf5de8c01f5075c19754cd7} isAuditEnabled={true} serviceType={null} resources={database={RangerPolicyResource={values={dcp } isExcludes={false} isRecursive={false} }} column={RangerPolicyResource={values={* } isExcludes={false} isRecursive={false} }} table={RangerPolicyResource={values={desensitize_a162c40cdc0140b1848b98415575be6c } isExcludes={false} isRecursive={false} }} } policyLabels={Consoler } policyConditions={} policyItems={RangerPolicyItem={accessTypes={RangerPolicyItemAccess={type={all} isAllowed={true} }} users={tangbiao2 } groups={} roles={} conditions={} delegateAdmin={false} }} denyPolicyItems={} allowExceptions={} denyExceptions={} dataMaskPolicyItems={} rowFilterPolicyItems={} options={} validitySchedules={, zoneName=null, isDenyAllElse={false} }}) failed
> javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
> Internal Exception: com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
> Error Code: 1213
> Call: INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (?, ?, ?, ?, ?, ?, ?)
> bind => [7 parameters bound]
> Query: ValueReadQuery(name="x_policy_ref_resource_SEQ" sql="SELECT LAST_INSERT_ID()")
> at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:868)
> at sun.reflect.GeneratedMethodAccessor98.invoke(Unknown Source)
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:301)
> at com.sun.proxy.$Proxy30.flush(Unknown Source)
> at org.apache.ranger.common.db.BaseDao.batchCreate(BaseDao.java:102)
> ...{noformat}
> mysql-deadlock：
> {noformat}
> ------------------------
> LATEST DETECTED DEADLOCK
> ------------------------
> 2022-03-21 09:47:22 0x7ff3a4859700
> *** (1) TRANSACTION:
> TRANSACTION 7036760, ACTIVE 0 sec inserting
> mysql tables in use 1, locked 1
> LOCK WAIT 23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
> MySQL thread id 27293, OS thread handle 140684415063808, query id 383930 192.168.0.76 DHCloudBG update
> INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13921, 5, 'database', '2022-03-20 12:47:22.681', 1)
> *** (1) WAITING FOR THIS LOCK TO BE GRANTED:
> RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036760 lock_mode X insert intention waiting
> Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
> 0: len 8; hex 73757072656d756d; asc supremum;;*** (2) TRANSACTION:
> TRANSACTION 7036759, ACTIVE 0 sec inserting
> mysql tables in use 1, locked 1
> 23 lock struct(s), heap size 1136, 12 row lock(s), undo log entries 2
> MySQL thread id 27295, OS thread handle 140684413998848, query id 383932 192.168.0.76 DHCloudBG update
> INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 12:47:22.666', 13920, 5, 'database', '2022-03-20 12:47:22.682', 1)
> *** (2) HOLDS THE LOCK(S):
> RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X
> Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
> 0: len 8; hex 73757072656d756d; asc supremum;;*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
> RECORD LOCKS space id 531 page no 4 n bits 376 index x_policy_ref_res_UK_polId_resDefId of table `ranger`.`x_policy_ref_resource` trx id 7036759 lock_mode X insert intention waiting
> Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
> 0: len 8; hex 73757072656d756d; asc supremum;;*** WE ROLL BACK TRANSACTION (2){noformat}
> h1. Descrition
> In our production enviroment, we may create ranger hive policy in parallel. In this case it will occasionally report deadlock errors. I turned on the general_log in mysql, and captured the sql when the deadlock exception occurred, as shown below (some sql was simplified, and only the sql that caused the deadlock was kept):
> {noformat}
> 2022-03-21T20:16:26.776033+08:00 239903 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032)
> 2022-03-21T20:16:26.776463+08:00 239902 Query DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033)
> 2022-03-21T20:16:26.784333+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1)
> 2022-03-21T20:16:26.785484+08:00 239902 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1)
> 2022-03-21T20:16:26.787844+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 8, 'column', '2022-03-20 23:16:26.786', 1)
> 2022-03-21T20:16:26.788728+08:00 239903 Query INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 6, 'table', '2022-03-20 23:16:26.787', 1)
> 2022-03-21T20:16:26.810405+08:00 239902 Query rollback
> 2022-03-21T20:16:26.810781+08:00 239902 Query SET autocommit=1
> 2022-03-21T20:16:26.831309+08:00 239903 Query commit{noformat}
> I exported the data in the x_policy_ref_resource table using mysqldump and simulated it in the local environment and found that there is a deadlock when the sql of the two transactions is executed as following order：
> ||transation1||transation2||
> |begin|begin|
> |DELETE FROM x_policy_ref_resource WHERE (policy_id = 16032);| |
> | |DELETE FROM x_policy_ref_resource WHERE (policy_id = 16033);|
> |INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.766', 16032, 5, 'database', '2022-03-20 23:16:26.783', 1);| |
> | |INSERT INTO x_policy_ref_resource (ADDED_BY_ID, CREATE_TIME, policy_id, resource_def_id, resource_name, UPDATE_TIME, UPD_BY_ID) VALUES (1, '2022-03-20 23:16:26.767', 16033, 5, 'database', '2022-03-20 23:16:26.784', 1);|
> # When transaction1 and transaction2 execute delete sql, they will both obtain gap lock, because gap locks are compatible.
> # Then transaction 1 executes insert sql, it will try to acquire the insert intention lock, which conflicts with the gap lock held by transaction 2, and enters the lock waiting state.
> # Finally, transaction2 executes insert sql, and also tries to acquire the insert intention lock, which conflicts with the gap lock held by transaction1. At this point, it is caught in a cycle where transaction1 waits for transaction 2 to release the gap lock, and transaction2 waits for transaction1 to release the gap lock. Two transactions waiting for each other to release locks eventually lead to a deadlock.
>
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