Uh oh!
There was an error while loading. Please reload this page.
Conversation
tuhaihe
commented
Jul 14, 2023
Member
Hi, @sandiandian can you update your PR's title to make it more clear? You can take the following template 'Title Module' as a reference: https://github.com/cloudberrydb/cloudberrydb/blob/d6605e473e30549b6dcd9ae019edeee6932fa3a2/.gitmessage#L1-L11 |
my-ship-it
approved these changes
Jul 19, 2023
tuhaihe
approved these changes
Jul 19, 2023
avamingli pushed a commit
to avamingli/cloudberrydb
that referenced
this pull request
Jan 21, 2025
## Problem An error occurs in python lib when a plpython function is executed. After our analysis, in the user's cluster, a plpython UDF was running with the unstable network, and got a timeout error: `failed to acquire resources on one or more segments`. Then a plpython UDF was run in the same session, and the UDF failed with GC error. Here is the core dump: ``` 2023-11-24 10:15:18.945507 CST,,,p2705198,th2081832064,,,,0,,,seg-1,,,,,"LOG","00000","3rd party error log: #0 0x7f7c68b6d55b in frame_dealloc /home/cc/repo/cpython/Objects/frameobject.c:509:5 #1 0x7f7c68b5109d in gen_send_ex /home/cc/repo/cpython/Objects/genobject.c:108:9 #2 0x7f7c68af9ddd in PyIter_Next /home/cc/repo/cpython/Objects/abstract.c:3118:14 #3 0x7f7c78caa5c0 in PLy_exec_function /home/cc/repo/gpdb6/src/pl/plpython/plpy_exec.c:134:11 #4 0x7f7c78cb5ffb in plpython_call_handler /home/cc/repo/gpdb6/src/pl/plpython/plpy_main.c:387:13 #5 0x562f5e008bb5 in ExecMakeTableFunctionResult /home/cc/repo/gpdb6/src/backend/executor/execQual.c:2395:13 #6 0x562f5e0dddec in FunctionNext_guts /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:142:5 #7 0x562f5e0da094 in FunctionNext /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:350:11 apache#8 0x562f5e03d4b0 in ExecScanFetch /home/cc/repo/gpdb6/src/backend/executor/execScan.c:84:9 apache#9 0x562f5e03cd8f in ExecScan /home/cc/repo/gpdb6/src/backend/executor/execScan.c:154:10 #10 0x562f5e0da072 in ExecFunctionScan /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:380:9 apache#11 0x562f5e001a1c in ExecProcNode /home/cc/repo/gpdb6/src/backend/executor/execProcnode.c:1071:13 apache#12 0x562f5dfe6377 in ExecutePlan /home/cc/repo/gpdb6/src/backend/executor/execMain.c:3202:10 apache#13 0x562f5dfe5bf4 in standard_ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:1171:5 apache#14 0x562f5dfe4877 in ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:992:4 apache#15 0x562f5e857e69 in PortalRunSelect /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1164:4 apache#16 0x562f5e856d3f in PortalRun /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1005:18 apache#17 0x562f5e84607a in exec_simple_query /home/cc/repo/gpdb6/src/backend/tcop/postgres.c:1848:10 ``` ## Reproduce We can use a simple procedure to reproduce the above problem: - set timeout GUC: `gpconfig -c gp_segment_connect_timeout -v 5` and `gpstop -ari` - prepare function: ``` CREATE EXTENSION plpythonu; CREATE OR REPLACE FUNCTION test_func() RETURNS SETOF int AS $$ plpy.execute("select pg_backend_pid()") for i in range(0, 5): yield (i) $$ LANGUAGE plpythonu; ``` - exit from the current psql session. - stop the postmaster of segment: `gdb -p "the pid of segment postmaster"` - enter a psql session. - call `SELECT test_func();` and get error ``` gpadmin=# select test_func(); ERROR: function "test_func" error fetching next item from iterator (plpy_elog.c:121) DETAIL: Exception: failed to acquire resources on one or more segments CONTEXT: Traceback (most recent call last): PL/Python function "test_func" ``` - quit gdb and make postmaster runnable. - call `SELECT test_func();` again and get panic ``` gpadmin=# SELECT test_func(); server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. The connection to the server was lost. Attempting reset: Failed. !> ``` ## Analysis - There is an SPI call in test_func(): `plpy.execute()`. - Then coordinator will start a subtransaction by PLy_spi_subtransaction_begin(); - Meanwhile, if the segment cannot receive the instruction from the coordinator, the subtransaction beginning procedure return fails. - BUT! The Python processor does not know whether an error happened and does not clean its environment. - Then the next plpython UDF in the same session will fail due to the wrong Python environment. ## Solution - Use try-catch to catch the exception caused by PLy_spi_subtransaction_begin() - set the python error indicator by PLy_spi_exception_set() Co-authored-by: Chen Mulong <chenmulong@gmail.com>
avamingli pushed a commit
to avamingli/cloudberrydb
that referenced
this pull request
Jan 21, 2025
## Problem An error occurs in python lib when a plpython function is executed. After our analysis, in the user's cluster, a plpython UDF was running with the unstable network, and got a timeout error: `failed to acquire resources on one or more segments`. Then a plpython UDF was run in the same session, and the UDF failed with GC error. Here is the core dump: ``` 2023-11-24 10:15:18.945507 CST,,,p2705198,th2081832064,,,,0,,,seg-1,,,,,"LOG","00000","3rd party error log: #0 0x7f7c68b6d55b in frame_dealloc /home/cc/repo/cpython/Objects/frameobject.c:509:5 #1 0x7f7c68b5109d in gen_send_ex /home/cc/repo/cpython/Objects/genobject.c:108:9 #2 0x7f7c68af9ddd in PyIter_Next /home/cc/repo/cpython/Objects/abstract.c:3118:14 #3 0x7f7c78caa5c0 in PLy_exec_function /home/cc/repo/gpdb6/src/pl/plpython/plpy_exec.c:134:11 #4 0x7f7c78cb5ffb in plpython_call_handler /home/cc/repo/gpdb6/src/pl/plpython/plpy_main.c:387:13 #5 0x562f5e008bb5 in ExecMakeTableFunctionResult /home/cc/repo/gpdb6/src/backend/executor/execQual.c:2395:13 #6 0x562f5e0dddec in FunctionNext_guts /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:142:5 #7 0x562f5e0da094 in FunctionNext /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:350:11 apache#8 0x562f5e03d4b0 in ExecScanFetch /home/cc/repo/gpdb6/src/backend/executor/execScan.c:84:9 apache#9 0x562f5e03cd8f in ExecScan /home/cc/repo/gpdb6/src/backend/executor/execScan.c:154:10 #10 0x562f5e0da072 in ExecFunctionScan /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:380:9 apache#11 0x562f5e001a1c in ExecProcNode /home/cc/repo/gpdb6/src/backend/executor/execProcnode.c:1071:13 apache#12 0x562f5dfe6377 in ExecutePlan /home/cc/repo/gpdb6/src/backend/executor/execMain.c:3202:10 apache#13 0x562f5dfe5bf4 in standard_ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:1171:5 apache#14 0x562f5dfe4877 in ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:992:4 apache#15 0x562f5e857e69 in PortalRunSelect /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1164:4 apache#16 0x562f5e856d3f in PortalRun /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1005:18 apache#17 0x562f5e84607a in exec_simple_query /home/cc/repo/gpdb6/src/backend/tcop/postgres.c:1848:10 ``` ## Reproduce We can use a simple procedure to reproduce the above problem: - set timeout GUC: `gpconfig -c gp_segment_connect_timeout -v 5` and `gpstop -ari` - prepare function: ``` CREATE EXTENSION plpythonu; CREATE OR REPLACE FUNCTION test_func() RETURNS SETOF int AS $$ plpy.execute("select pg_backend_pid()") for i in range(0, 5): yield (i) $$ LANGUAGE plpythonu; ``` - exit from the current psql session. - stop the postmaster of segment: `gdb -p "the pid of segment postmaster"` - enter a psql session. - call `SELECT test_func();` and get error ``` gpadmin=# select test_func(); ERROR: function "test_func" error fetching next item from iterator (plpy_elog.c:121) DETAIL: Exception: failed to acquire resources on one or more segments CONTEXT: Traceback (most recent call last): PL/Python function "test_func" ``` - quit gdb and make postmaster runnable. - call `SELECT test_func();` again and get panic ``` gpadmin=# SELECT test_func(); server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. The connection to the server was lost. Attempting reset: Failed. !> ``` ## Analysis - There is an SPI call in test_func(): `plpy.execute()`. - Then coordinator will start a subtransaction by PLy_spi_subtransaction_begin(); - Meanwhile, if the segment cannot receive the instruction from the coordinator, the subtransaction beginning procedure return fails. - BUT! The Python processor does not know whether an error happened and does not clean its environment. - Then the next plpython UDF in the same session will fail due to the wrong Python environment. ## Solution - Use try-catch to catch the exception caused by PLy_spi_subtransaction_begin() - set the python error indicator by PLy_spi_exception_set() Co-authored-by: Chen Mulong <chenmulong@gmail.com>
avamingli pushed a commit
to avamingli/cloudberrydb
that referenced
this pull request
Jan 22, 2025
## Problem An error occurs in python lib when a plpython function is executed. After our analysis, in the user's cluster, a plpython UDF was running with the unstable network, and got a timeout error: `failed to acquire resources on one or more segments`. Then a plpython UDF was run in the same session, and the UDF failed with GC error. Here is the core dump: ``` 2023-11-24 10:15:18.945507 CST,,,p2705198,th2081832064,,,,0,,,seg-1,,,,,"LOG","00000","3rd party error log: #0 0x7f7c68b6d55b in frame_dealloc /home/cc/repo/cpython/Objects/frameobject.c:509:5 #1 0x7f7c68b5109d in gen_send_ex /home/cc/repo/cpython/Objects/genobject.c:108:9 #2 0x7f7c68af9ddd in PyIter_Next /home/cc/repo/cpython/Objects/abstract.c:3118:14 #3 0x7f7c78caa5c0 in PLy_exec_function /home/cc/repo/gpdb6/src/pl/plpython/plpy_exec.c:134:11 #4 0x7f7c78cb5ffb in plpython_call_handler /home/cc/repo/gpdb6/src/pl/plpython/plpy_main.c:387:13 #5 0x562f5e008bb5 in ExecMakeTableFunctionResult /home/cc/repo/gpdb6/src/backend/executor/execQual.c:2395:13 #6 0x562f5e0dddec in FunctionNext_guts /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:142:5 #7 0x562f5e0da094 in FunctionNext /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:350:11 apache#8 0x562f5e03d4b0 in ExecScanFetch /home/cc/repo/gpdb6/src/backend/executor/execScan.c:84:9 apache#9 0x562f5e03cd8f in ExecScan /home/cc/repo/gpdb6/src/backend/executor/execScan.c:154:10 #10 0x562f5e0da072 in ExecFunctionScan /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:380:9 apache#11 0x562f5e001a1c in ExecProcNode /home/cc/repo/gpdb6/src/backend/executor/execProcnode.c:1071:13 apache#12 0x562f5dfe6377 in ExecutePlan /home/cc/repo/gpdb6/src/backend/executor/execMain.c:3202:10 apache#13 0x562f5dfe5bf4 in standard_ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:1171:5 apache#14 0x562f5dfe4877 in ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:992:4 apache#15 0x562f5e857e69 in PortalRunSelect /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1164:4 apache#16 0x562f5e856d3f in PortalRun /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1005:18 apache#17 0x562f5e84607a in exec_simple_query /home/cc/repo/gpdb6/src/backend/tcop/postgres.c:1848:10 ``` ## Reproduce We can use a simple procedure to reproduce the above problem: - set timeout GUC: `gpconfig -c gp_segment_connect_timeout -v 5` and `gpstop -ari` - prepare function: ``` CREATE EXTENSION plpythonu; CREATE OR REPLACE FUNCTION test_func() RETURNS SETOF int AS $$ plpy.execute("select pg_backend_pid()") for i in range(0, 5): yield (i) $$ LANGUAGE plpythonu; ``` - exit from the current psql session. - stop the postmaster of segment: `gdb -p "the pid of segment postmaster"` - enter a psql session. - call `SELECT test_func();` and get error ``` gpadmin=# select test_func(); ERROR: function "test_func" error fetching next item from iterator (plpy_elog.c:121) DETAIL: Exception: failed to acquire resources on one or more segments CONTEXT: Traceback (most recent call last): PL/Python function "test_func" ``` - quit gdb and make postmaster runnable. - call `SELECT test_func();` again and get panic ``` gpadmin=# SELECT test_func(); server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. The connection to the server was lost. Attempting reset: Failed. !> ``` ## Analysis - There is an SPI call in test_func(): `plpy.execute()`. - Then coordinator will start a subtransaction by PLy_spi_subtransaction_begin(); - Meanwhile, if the segment cannot receive the instruction from the coordinator, the subtransaction beginning procedure return fails. - BUT! The Python processor does not know whether an error happened and does not clean its environment. - Then the next plpython UDF in the same session will fail due to the wrong Python environment. ## Solution - Use try-catch to catch the exception caused by PLy_spi_subtransaction_begin() - set the python error indicator by PLy_spi_exception_set() Co-authored-by: Chen Mulong <chenmulong@gmail.com>
avamingli pushed a commit
that referenced
this pull request
Jan 23, 2025
## Problem An error occurs in python lib when a plpython function is executed. After our analysis, in the user's cluster, a plpython UDF was running with the unstable network, and got a timeout error: `failed to acquire resources on one or more segments`. Then a plpython UDF was run in the same session, and the UDF failed with GC error. Here is the core dump: ``` 2023-11-24 10:15:18.945507 CST,,,p2705198,th2081832064,,,,0,,,seg-1,,,,,"LOG","00000","3rd party error log: #0 0x7f7c68b6d55b in frame_dealloc /home/cc/repo/cpython/Objects/frameobject.c:509:5 #1 0x7f7c68b5109d in gen_send_ex /home/cc/repo/cpython/Objects/genobject.c:108:9 #2 0x7f7c68af9ddd in PyIter_Next /home/cc/repo/cpython/Objects/abstract.c:3118:14 #3 0x7f7c78caa5c0 in PLy_exec_function /home/cc/repo/gpdb6/src/pl/plpython/plpy_exec.c:134:11 #4 0x7f7c78cb5ffb in plpython_call_handler /home/cc/repo/gpdb6/src/pl/plpython/plpy_main.c:387:13 #5 0x562f5e008bb5 in ExecMakeTableFunctionResult /home/cc/repo/gpdb6/src/backend/executor/execQual.c:2395:13 #6 0x562f5e0dddec in FunctionNext_guts /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:142:5 #7 0x562f5e0da094 in FunctionNext /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:350:11 #8 0x562f5e03d4b0 in ExecScanFetch /home/cc/repo/gpdb6/src/backend/executor/execScan.c:84:9 #9 0x562f5e03cd8f in ExecScan /home/cc/repo/gpdb6/src/backend/executor/execScan.c:154:10 #10 0x562f5e0da072 in ExecFunctionScan /home/cc/repo/gpdb6/src/backend/executor/nodeFunctionscan.c:380:9 #11 0x562f5e001a1c in ExecProcNode /home/cc/repo/gpdb6/src/backend/executor/execProcnode.c:1071:13 #12 0x562f5dfe6377 in ExecutePlan /home/cc/repo/gpdb6/src/backend/executor/execMain.c:3202:10 #13 0x562f5dfe5bf4 in standard_ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:1171:5 #14 0x562f5dfe4877 in ExecutorRun /home/cc/repo/gpdb6/src/backend/executor/execMain.c:992:4 #15 0x562f5e857e69 in PortalRunSelect /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1164:4 #16 0x562f5e856d3f in PortalRun /home/cc/repo/gpdb6/src/backend/tcop/pquery.c:1005:18 #17 0x562f5e84607a in exec_simple_query /home/cc/repo/gpdb6/src/backend/tcop/postgres.c:1848:10 ``` ## Reproduce We can use a simple procedure to reproduce the above problem: - set timeout GUC: `gpconfig -c gp_segment_connect_timeout -v 5` and `gpstop -ari` - prepare function: ``` CREATE EXTENSION plpythonu; CREATE OR REPLACE FUNCTION test_func() RETURNS SETOF int AS $$ plpy.execute("select pg_backend_pid()") for i in range(0, 5): yield (i) $$ LANGUAGE plpythonu; ``` - exit from the current psql session. - stop the postmaster of segment: `gdb -p "the pid of segment postmaster"` - enter a psql session. - call `SELECT test_func();` and get error ``` gpadmin=# select test_func(); ERROR: function "test_func" error fetching next item from iterator (plpy_elog.c:121) DETAIL: Exception: failed to acquire resources on one or more segments CONTEXT: Traceback (most recent call last): PL/Python function "test_func" ``` - quit gdb and make postmaster runnable. - call `SELECT test_func();` again and get panic ``` gpadmin=# SELECT test_func(); server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. The connection to the server was lost. Attempting reset: Failed. !> ``` ## Analysis - There is an SPI call in test_func(): `plpy.execute()`. - Then coordinator will start a subtransaction by PLy_spi_subtransaction_begin(); - Meanwhile, if the segment cannot receive the instruction from the coordinator, the subtransaction beginning procedure return fails. - BUT! The Python processor does not know whether an error happened and does not clean its environment. - Then the next plpython UDF in the same session will fail due to the wrong Python environment. ## Solution - Use try-catch to catch the exception caused by PLy_spi_subtransaction_begin() - set the python error indicator by PLy_spi_exception_set() Co-authored-by: Chen Mulong <chenmulong@gmail.com>
12 tasks
NJrslv referenced
this pull request
in open-gpdb/cloudberry
Jan 15, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
add cicd pipeline
Fix: remove qingcloud platform-specific unit-tests