From a9b65bfd1f55467fb597df33c0952680473d9f87 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy Date: Wed, 30 Nov 2022 05:43:06 +0000 Subject: [PATCH v22] Add documentation and tests for pg_log_backtrace() --- doc/src/sgml/func.sgml | 76 +++++++++++++++++++++++ src/test/regress/expected/backtrace.out | 49 +++++++++++++++ src/test/regress/expected/backtrace_1.out | 55 ++++++++++++++++ src/test/regress/parallel_schedule | 2 +- src/test/regress/sql/backtrace.sql | 33 ++++++++++ 5 files changed, 214 insertions(+), 1 deletion(-) create mode 100644 src/test/regress/expected/backtrace.out create mode 100644 src/test/regress/expected/backtrace_1.out create mode 100644 src/test/regress/sql/backtrace.sql diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 22204f16c2..f5baae952c 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -25482,6 +25482,27 @@ SELECT collation for ('foo' COLLATE "de_DE"); + + + + pg_log_backtrace + + pg_log_backtrace ( pid integer ) + boolean + + + Requests to log the backtrace of the backend with the specified + process ID. This function can send the request to backends and + auxiliary processes except the logger and statistics collector. + The backtraces will be logged to stderr. + Typically, a backtrace identifies which function a process is + currently executing and it is useful for developers to diagnose + stuck processes and other problems. This function is supported + only if PostgreSQL was built with the ability to capture backtraces, + otherwise it will emit a warning. + + + @@ -25702,6 +25723,61 @@ LOG: Grand total: 1651920 bytes in 201 blocks; 622360 free (88 chunks); 1029560 because it may generate a large number of log messages. + + pg_log_backtrace can be used to log the backtrace of + a backend process. For example: + +postgres=# select pg_log_backtrace(pg_backend_pid()); + pg_log_backtrace +------------------ + t +(1 row) + +The backtrace will be logged as specified by the logging configuration. +For example: + +logging current backtrace of process with PID 3499242: +postgres: ubuntu postgres [local] INSERT(+0x61a355)[0x5559b94de355] +postgres: ubuntu postgres [local] INSERT(procsignal_sigusr1_handler+0x9e)[0x5559b94de4ef] +/lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7f7e9c0e8520] +postgres: ubuntu postgres [local] INSERT(+0x868004)[0x5559b972c004] +postgres: ubuntu postgres [local] INSERT(pfree+0x1c)[0x5559b972e445] +postgres: ubuntu postgres [local] INSERT(heap_free_minimal_tuple+0x1c)[0x5559b8fa7b48] +postgres: ubuntu postgres [local] INSERT(+0x8826d6)[0x5559b97466d6] +postgres: ubuntu postgres [local] INSERT(+0x881126)[0x5559b9745126] +postgres: ubuntu postgres [local] INSERT(tuplestore_putvalues+0x83)[0x5559b9744ed5] +postgres: ubuntu postgres [local] INSERT(ExecMakeTableFunctionResult+0x68b)[0x5559b9284295] +postgres: ubuntu postgres [local] INSERT(+0x3dd14a)[0x5559b92a114a] +postgres: ubuntu postgres [local] INSERT(+0x3c1a5c)[0x5559b9285a5c] +postgres: ubuntu postgres [local] INSERT(ExecScan+0x77)[0x5559b9285ad5] +postgres: ubuntu postgres [local] INSERT(+0x3dd4f4)[0x5559b92a14f4] +postgres: ubuntu postgres [local] INSERT(+0x3bd485)[0x5559b9281485] +postgres: ubuntu postgres [local] INSERT(+0x3f96f0)[0x5559b92bd6f0] +postgres: ubuntu postgres [local] INSERT(+0x3ff25e)[0x5559b92c325e] +postgres: ubuntu postgres [local] INSERT(+0x3bd485)[0x5559b9281485] +postgres: ubuntu postgres [local] INSERT(+0x3b07a4)[0x5559b92747a4] +postgres: ubuntu postgres [local] INSERT(+0x3b3594)[0x5559b9277594] +postgres: ubuntu postgres [local] INSERT(standard_ExecutorRun+0x1f4)[0x5559b9274e8c] +postgres: ubuntu postgres [local] INSERT(ExecutorRun+0x5d)[0x5559b9274c95] +postgres: ubuntu postgres [local] INSERT(+0x64ee3a)[0x5559b9512e3a] +postgres: ubuntu postgres [local] INSERT(+0x6509c9)[0x5559b95149c9] +postgres: ubuntu postgres [local] INSERT(PortalRun+0x378)[0x5559b9513ec0] +postgres: ubuntu postgres [local] INSERT(+0x648c56)[0x5559b950cc56] +postgres: ubuntu postgres [local] INSERT(PostgresMain+0x80c)[0x5559b9511c46] +postgres: ubuntu postgres [local] INSERT(+0x576647)[0x5559b943a647] +postgres: ubuntu postgres [local] INSERT(+0x575ed3)[0x5559b9439ed3] +postgres: ubuntu postgres [local] INSERT(+0x572388)[0x5559b9436388] +postgres: ubuntu postgres [local] INSERT(PostmasterMain+0x14b3)[0x5559b9435ae5] +postgres: ubuntu postgres [local] INSERT(+0x43b563)[0x5559b92ff563] +/lib/x86_64-linux-gnu/libc.so.6(+0x29d90)[0x7f7e9c0cfd90] +/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x80)[0x7f7e9c0cfe40] +postgres: ubuntu postgres [local] INSERT(_start+0x25)[0x5559b8f8f005] + + One can obtain the file name and line number from the logged details by using + gdb/addr2line in linux platforms (users must ensure gdb/addr2line is + already installed). + + diff --git a/src/test/regress/expected/backtrace.out b/src/test/regress/expected/backtrace.out new file mode 100644 index 0000000000..5341a6adfe --- /dev/null +++ b/src/test/regress/expected/backtrace.out @@ -0,0 +1,49 @@ +-- +-- pg_log_backtrace() +-- +-- Backtraces are logged to stderr and not returned to the function. +-- Furthermore, their contents can vary depending on the timing. However, +-- we can at least verify that the code doesn't fail, and that the +-- permissions are set properly. +-- +SELECT pg_log_backtrace(pg_backend_pid()); + pg_log_backtrace +------------------ + t +(1 row) + +SELECT pg_log_backtrace(pid) FROM pg_stat_activity + WHERE backend_type = 'checkpointer'; + pg_log_backtrace +------------------ + t +(1 row) + +CREATE ROLE regress_log_backtrace; +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- no + has_function_privilege +------------------------ + f +(1 row) + +GRANT EXECUTE ON FUNCTION pg_log_backtrace(integer) + TO regress_log_backtrace; +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- yes + has_function_privilege +------------------------ + t +(1 row) + +SET ROLE regress_log_backtrace; +SELECT pg_log_backtrace(pg_backend_pid()); + pg_log_backtrace +------------------ + t +(1 row) + +RESET ROLE; +REVOKE EXECUTE ON FUNCTION pg_log_backtrace(integer) + FROM regress_log_backtrace; +DROP ROLE regress_log_backtrace; diff --git a/src/test/regress/expected/backtrace_1.out b/src/test/regress/expected/backtrace_1.out new file mode 100644 index 0000000000..899f330224 --- /dev/null +++ b/src/test/regress/expected/backtrace_1.out @@ -0,0 +1,55 @@ +-- +-- pg_log_backtrace() +-- +-- Backtraces are logged to stderr and not returned to the function. +-- Furthermore, their contents can vary depending on the timing. However, +-- we can at least verify that the code doesn't fail, and that the +-- permissions are set properly. +-- +SELECT pg_log_backtrace(pg_backend_pid()); +WARNING: backtrace generation is not supported by this installation +HINT: You need to rebuild PostgreSQL using a library containing backtrace_symbols. + pg_log_backtrace +------------------ + f +(1 row) + +SELECT pg_log_backtrace(pid) FROM pg_stat_activity + WHERE backend_type = 'checkpointer'; +WARNING: backtrace generation is not supported by this installation +HINT: You need to rebuild PostgreSQL using a library containing backtrace_symbols. + pg_log_backtrace +------------------ + f +(1 row) + +CREATE ROLE regress_log_backtrace; +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- no + has_function_privilege +------------------------ + f +(1 row) + +GRANT EXECUTE ON FUNCTION pg_log_backtrace(integer) + TO regress_log_backtrace; +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- yes + has_function_privilege +------------------------ + t +(1 row) + +SET ROLE regress_log_backtrace; +SELECT pg_log_backtrace(pg_backend_pid()); +WARNING: backtrace generation is not supported by this installation +HINT: You need to rebuild PostgreSQL using a library containing backtrace_symbols. + pg_log_backtrace +------------------ + f +(1 row) + +RESET ROLE; +REVOKE EXECUTE ON FUNCTION pg_log_backtrace(integer) + FROM regress_log_backtrace; +DROP ROLE regress_log_backtrace; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index 9a139f1e24..c0f388300c 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -86,7 +86,7 @@ test: brin_bloom brin_multi # psql depends on create_am # amutils depends on geometry, create_index_spgist, hash_index, brin # ---------- -test: create_table_like alter_generic alter_operator misc async dbsize merge misc_functions sysviews tsrf tid tidscan tidrangescan collate.icu.utf8 incremental_sort create_role +test: create_table_like alter_generic alter_operator misc async dbsize merge misc_functions sysviews tsrf tid tidscan tidrangescan collate.icu.utf8 incremental_sort create_role backtrace # collate.*.utf8 tests cannot be run in parallel with each other test: rules psql psql_crosstab amutils stats_ext collate.linux.utf8 diff --git a/src/test/regress/sql/backtrace.sql b/src/test/regress/sql/backtrace.sql new file mode 100644 index 0000000000..674e41c998 --- /dev/null +++ b/src/test/regress/sql/backtrace.sql @@ -0,0 +1,33 @@ +-- +-- pg_log_backtrace() +-- +-- Backtraces are logged to stderr and not returned to the function. +-- Furthermore, their contents can vary depending on the timing. However, +-- we can at least verify that the code doesn't fail, and that the +-- permissions are set properly. +-- + +SELECT pg_log_backtrace(pg_backend_pid()); + +SELECT pg_log_backtrace(pid) FROM pg_stat_activity + WHERE backend_type = 'checkpointer'; + +CREATE ROLE regress_log_backtrace; + +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- no + +GRANT EXECUTE ON FUNCTION pg_log_backtrace(integer) + TO regress_log_backtrace; + +SELECT has_function_privilege('regress_log_backtrace', + 'pg_log_backtrace(integer)', 'EXECUTE'); -- yes + +SET ROLE regress_log_backtrace; +SELECT pg_log_backtrace(pg_backend_pid()); +RESET ROLE; + +REVOKE EXECUTE ON FUNCTION pg_log_backtrace(integer) + FROM regress_log_backtrace; + +DROP ROLE regress_log_backtrace; -- 2.34.1