Backport #87614 to 25.9: Small fixes for jemalloc profiler

robot-clickhouse · robot-clickhouse · commit af88a110d2e8 · 2025-09-27T22:10:11.000Z
diff --git a/docs/en/operations/allocation-profiling.md b/docs/en/operations/allocation-profiling.md
@@ -189,11 +189,6 @@ SYSTEM JEMALLOC FLUSH PROFILE
 
 It will return the location of the flushed profile.
 
-You can also specify a different prefix for the file in the query:
-```sql
-SYSTEM JEMALLOC FLUSH PROFILE TO '/tmp/my_own_prefix'
-```
-
 </TabItem>
 <TabItem value="keeper" label="Keeper">
     
diff --git a/programs/local/LocalServer.cpp b/programs/local/LocalServer.cpp
@@ -35,6 +35,7 @@
 #include <Common/ThreadPool.h>
 #include <Common/CurrentMetrics.h>
 #include <Common/NamedCollections/NamedCollectionsFactory.h>
+#include <Common/Jemalloc.h>
 #include <Interpreters/Cache/FileCacheFactory.h>
 #include <Loggers/OwnFormattingChannel.h>
 #include <Loggers/OwnPatternFormatter.h>
@@ -134,6 +135,10 @@ namespace ServerSetting
     extern const ServerSettingsUInt64 max_format_parsing_thread_pool_free_size;
     extern const ServerSettingsUInt64 format_parsing_thread_pool_queue_size;
     extern const ServerSettingsString allowed_disks_for_table_engines;
+    extern const ServerSettingsBool jemalloc_enable_global_profiler;
+    extern const ServerSettingsBool jemalloc_collect_global_profile_samples_in_trace_log;
+    extern const ServerSettingsBool jemalloc_enable_background_threads;
+    extern const ServerSettingsUInt64 jemalloc_max_background_threads_num;
 }
 
 namespace ErrorCodes
@@ -216,6 +221,14 @@ void LocalServer::initialize(Poco::Util::Application & self)
 
     server_settings.loadSettingsFromConfig(config());
 
+#if USE_JEMALLOC
+    Jemalloc::setup(
+        server_settings[ServerSetting::jemalloc_enable_global_profiler],
+        server_settings[ServerSetting::jemalloc_enable_background_threads],
+        server_settings[ServerSetting::jemalloc_max_background_threads_num],
+        server_settings[ServerSetting::jemalloc_collect_global_profile_samples_in_trace_log]);
+#endif
+
     GlobalThreadPool::initialize(
         server_settings[ServerSetting::max_thread_pool_size],
         server_settings[ServerSetting::max_thread_pool_free_size],
diff --git a/src/Core/ServerSettings.cpp b/src/Core/ServerSettings.cpp
@@ -1122,9 +1122,12 @@ The policy on how to perform a scheduling of CPU slots specified by `concurrent_
     DECLARE(Bool, abort_on_logical_error, false, R"(Crash the server on LOGICAL_ERROR exceptions. Only for experts.)", 0) \
     DECLARE(UInt64, jemalloc_flush_profile_interval_bytes, 0, R"(Flushing jemalloc profile will be done after global peak memory usage increased by jemalloc_flush_profile_interval_bytes)", 0) \
     DECLARE(Bool, jemalloc_flush_profile_on_memory_exceeded, 0, R"(Flushing jemalloc profile will be done on total memory exceeded errors)", 0) \
-    DECLARE(Bool, jemalloc_enable_global_profiler, 0, R"(Enable jemalloc profiler)", 0) \
-    DECLARE(Bool, jemalloc_collect_global_profile_samples_in_trace_log, 0, R"(Store jemalloc sampled allocations in system.trace_log)", 0) \
-    DECLARE(Bool, jemalloc_enable_background_threads, 1, R"(Enable jemalloc background threads)", 0) \
+    DECLARE(Bool, jemalloc_enable_global_profiler, 0, R"(Enable jemalloc's allocation profiler for all threads. Jemalloc will sample allocations and all deallocations for sampled allocations.
+    Profiles can be flushed using SYSTEM JEMALLOC FLUSH PROFILE which can be used for allocation analysis.
+    Samples can also be stored in system.trace_log using config jemalloc_collect_global_profile_samples_in_trace_log or with query setting jemalloc_collect_profile_samples_in_trace_log.
+    See [Allocation Profiling](/operations/allocation-profiling))", 0) \
+    DECLARE(Bool, jemalloc_collect_global_profile_samples_in_trace_log, 0, R"(Store jemalloc's sampled allocations in system.trace_log)", 0) \
+    DECLARE(Bool, jemalloc_enable_background_threads, 1, R"(Enable jemalloc background threads. Jemalloc uses background threads to cleanup unused memory pages. Disabling it could lead to performance degradation.)", 0) \
     DECLARE(UInt64, jemalloc_max_background_threads_num, 0, R"(Maximum amount of jemalloc background threads to create, set to 0 to use jemalloc's default value)", 0) \
     DECLARE(NonZeroUInt64, threadpool_local_fs_reader_pool_size, 100, R"(The number of threads in the thread pool for reading from local filesystem when `local_filesystem_read_method = 'pread_threadpool'`.)", 0) \
     DECLARE(UInt64, threadpool_local_fs_reader_queue_size, 1000000, R"(The maximum number of jobs that can be scheduled on the thread pool for reading from local filesystem.)", 0) \
@@ -1153,7 +1156,7 @@ The policy on how to perform a scheduling of CPU slots specified by `concurrent_
     Requires CAP_SYS_NICE capability, otherwise no-op.
 
     Possible values: -20 to 19.
-    )", 0) \
+    )", 0)
 
 // clang-format on
 
diff --git a/src/Core/Settings.cpp b/src/Core/Settings.cpp
@@ -6886,10 +6886,12 @@ Possible values:
 - 1 - For `Date32` the result is always `Date`. For `DateTime64` the result is `DateTime` for time units `second` and higher.
 )", 0) \
     DECLARE(Bool, jemalloc_enable_profiler, false, R"(
-Enable jemalloc profiler.
-    )", 0) \
+Enable jemalloc profiler for the query. Jemalloc will sample allocations and all deallocations for sampled allocations.
+Profiles can be flushed using SYSTEM JEMALLOC FLUSH PROFILE which can be used for allocation analysis.
+Samples can also be stored in system.trace_log using config jemalloc_collect_global_profile_samples_in_trace_log or with query setting jemalloc_collect_profile_samples_in_trace_log.
+See [Allocation Profiling](/operations/allocation-profiling))", 0) \
     DECLARE(Bool, jemalloc_collect_profile_samples_in_trace_log, false, R"(
-Collect jemalloc profile samples in trace log.
+Collect jemalloc allocation and deallocation samples in trace log.
     )", 0) \
     DECLARE_WITH_ALIAS(Int32, os_threads_nice_value_query, 0, R"(
 Linux nice value for query processing threads. Lower values mean higher CPU priority.
diff --git a/src/Interpreters/InterpreterSystemQuery.cpp b/src/Interpreters/InterpreterSystemQuery.cpp
@@ -915,8 +915,7 @@ BlockIO InterpreterSystemQuery::execute()
         case Type::JEMALLOC_FLUSH_PROFILE:
         {
             getContext()->checkAccess(AccessType::SYSTEM_JEMALLOC);
-            Jemalloc::flushProfile(query.jemalloc_profile_path.empty() ? "/tmp/jemalloc_clickhouse" : query.jemalloc_profile_path);
-            auto filename = Jemalloc::getLastFlushProfileForThread();
+            auto filename = Jemalloc::flushProfile("/tmp/jemalloc_clickhouse");
             auto col = ColumnString::create();
             col->insertData(filename.data(), filename.size());
             Columns columns;
diff --git a/src/Parsers/ASTSystemQuery.cpp b/src/Parsers/ASTSystemQuery.cpp
@@ -468,17 +468,6 @@ void ASTSystemQuery::formatImpl(WriteBuffer & ostr, const FormatSettings & setti
             }
             break;
         }
-        case Type::JEMALLOC_FLUSH_PROFILE:
-        {
-#if USE_JEMALLOC
-            if (!jemalloc_profile_path.empty())
-            {
-                print_keyword(" TO ");
-                ostr << quoteString(jemalloc_profile_path);
-            }
-#endif
-            break;
-        }
         case Type::KILL:
         case Type::SHUTDOWN:
         case Type::DROP_DNS_CACHE:
@@ -498,6 +487,7 @@ void ASTSystemQuery::formatImpl(WriteBuffer & ostr, const FormatSettings & setti
         case Type::RESET_COVERAGE:
         case Type::RESTART_REPLICAS:
         case Type::JEMALLOC_PURGE:
+        case Type::JEMALLOC_FLUSH_PROFILE:
         case Type::JEMALLOC_ENABLE_PROFILE:
         case Type::JEMALLOC_DISABLE_PROFILE:
         case Type::SYNC_TRANSACTION_LOG:
diff --git a/src/Parsers/ASTSystemQuery.h b/src/Parsers/ASTSystemQuery.h
@@ -1,7 +1,5 @@
 #pragma once
 
-#include "config.h"
-
 #include <Parsers/ASTQueryWithOnCluster.h>
 #include <Parsers/IAST.h>
 #include <Parsers/SyncReplicaMode.h>
@@ -177,10 +175,6 @@ class ASTSystemQuery : public IAST, public ASTQueryWithOnCluster
 
     ServerType server_type;
 
-#if USE_JEMALLOC
-    String jemalloc_profile_path;
-#endif
-
     /// For SYSTEM TEST VIEW <name> (SET FAKE TIME <time> | UNSET FAKE TIME).
     /// Unix time.
     std::optional<Int64> fake_time_for_view;
diff --git a/src/Parsers/ParserSystemQuery.cpp b/src/Parsers/ParserSystemQuery.cpp
@@ -753,14 +753,6 @@ bool ParserSystemQuery::parseImpl(IParser::Pos & pos, ASTPtr & node, Expected &
                 if (!parseQueryWithOnCluster(res, pos, expected))
                     return false;
             }
-
-            if (ParserKeyword{Keyword::TO}.ignore(pos, expected))
-            {
-                ASTPtr ast;
-                if (ParserStringLiteral{}.parse(pos, ast, expected))
-                    res->jemalloc_profile_path = ast->as<ASTLiteral &>().value.safeGet<String>();
-            }
-
             break;
         }
 #endif
diff --git a/tests/queries/0_stateless/03631_local_jemalloc_flush_profile.reference b/tests/queries/0_stateless/03631_local_jemalloc_flush_profile.reference
diff --git a/tests/queries/0_stateless/03631_local_jemalloc_flush_profile.sh b/tests/queries/0_stateless/03631_local_jemalloc_flush_profile.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+# Tags: no-tsan, no-asan, no-msan, no-ubsan, no-fasttest
+#       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+# NOTE: jemalloc is disabled under sanitizers
+
+CUR_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CUR_DIR"/../shell_config.sh
+
+$CLICKHOUSE_LOCAL --query "SYSTEM JEMALLOC FLUSH PROFILE" -- --enable_jemalloc_global_profiler | grep -q ".heap" || echo "Didn't return profile path"
