--- machine_translated: true machine_translated_rev: 72537a2d527c63c07aa5d2361a8829f3895cf2bd sidebar_position: 65 sidebar_label: "\u81EA\u7701" --- # 内省功能 {#introspection-functions} 您可以使用本章中描述的函数来反省 [ELF](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format) 和 [DWARF](https://en.wikipedia.org/wiki/DWARF) 用于查询分析。 !!! warning "警告" 这些功能很慢，可能会强加安全考虑。 对于内省功能的正确操作: - 安装 `clickhouse-common-static-dbg` 包。 - 设置 [allow_introspection_functions](../../operations/settings/settings.md#settings-allow_introspection_functions) 设置为1。 出于安全考虑，内省函数默认是关闭的。 ClickHouse将探查器报告保存到 [trace_log](../../operations/system-tables/trace_log.md#system_tables-trace_log) 系统表. 确保正确配置了表和探查器。 ## addressToLine {#addresstoline} 将ClickHouse服务器进程内的虚拟内存地址转换为ClickHouse源代码中的文件名和行号。 如果您使用官方的ClickHouse软件包，您需要安装 `clickhouse-common-static-dbg` 包。 **语法** ``` sql addressToLine(address_of_binary_instruction) ``` **参数** - `address_of_binary_instruction` ([UInt64](../../sql-reference/data-types/int-uint.md)) — 正在运行进程的指令地址。 **返回值** - 源代码文件名和行号（用冒号分隔的行号） 示例, `/build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199`, where `199` is a line number. - 如果函数找不到调试信息，返回二进制文件的名称。 - 如果地址无效，返回空字符串。 类型: [字符串](../../sql-reference/data-types/string.md). **示例** 启用内省功能: ``` sql SET allow_introspection_functions=1 ``` 从中选择第一个字符串 `trace_log` 系统表: ``` sql SELECT * FROM system.trace_log LIMIT 1 \G ``` ``` text Row 1: ────── event_date: 2019-11-19 event_time: 2019-11-19 18:57:23 revision: 54429 timer_type: Real thread_number: 48 query_id: 421b6855-1858-45a5-8f37-f383409d6d72 trace: [140658411141617,94784174532828,94784076370703,94784076372094,94784076361020,94784175007680,140658411116251,140658403895439] ``` 该 `trace` 字段包含采样时的堆栈跟踪。 获取单个地址的源代码文件名和行号: ``` sql SELECT addressToLine(94784076370703) \G ``` ``` text Row 1: ────── addressToLine(94784076370703): /build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199 ``` 将函数应用于整个堆栈跟踪: ``` sql SELECT arrayStringConcat(arrayMap(x -> addressToLine(x), trace), '\n') AS trace_source_code_lines FROM system.trace_log LIMIT 1 \G ``` 该 [arrayMap](higher-order-functions.md#higher_order_functions-array-map) 功能允许处理的每个单独的元素 `trace` 阵列由 `addressToLine` 功能。 这种处理的结果，你在看 `trace_source_code_lines` 列的输出。 ``` text Row 1: ────── trace_source_code_lines: /lib/x86_64-linux-gnu/libpthread-2.27.so /usr/lib/debug/usr/bin/clickhouse /build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199 /build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.h:155 /usr/include/c++/9/bits/atomic_base.h:551 /usr/lib/debug/usr/bin/clickhouse /lib/x86_64-linux-gnu/libpthread-2.27.so /build/glibc-OTsEL5/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:97 ``` ## addressToSymbol {#addresstosymbol} 将ClickHouse服务器进程内的虚拟内存地址转换为ClickHouse对象文件中的符号。 **语法** ``` sql addressToSymbol(address_of_binary_instruction) ``` **参数** - `address_of_binary_instruction` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Address of instruction in a running process. **返回值** - 来自ClickHouse对象文件的符号。 - 如果地址无效，返回空字符串。 类型: [字符串](../../sql-reference/data-types/string.md). **示例** 启用内省功能: ``` sql SET allow_introspection_functions=1 ``` 从中选择第一个字符串 `trace_log` 系统表: ``` sql SELECT * FROM system.trace_log LIMIT 1 \G ``` ``` text Row 1: ────── event_date: 2019-11-20 event_time: 2019-11-20 16:57:59 revision: 54429 timer_type: Real thread_number: 48 query_id: 724028bf-f550-45aa-910d-2af6212b94ac trace: [94138803686098,94138815010911,94138815096522,94138815101224,94138815102091,94138814222988,94138806823642,94138814457211,94138806823642,94138814457211,94138806823642,94138806795179,94138806796144,94138753770094,94138753771646,94138753760572,94138852407232,140399185266395,140399178045583] ``` 该 `trace` 字段包含采样时的堆栈跟踪。 获取单个地址的符号: ``` sql SELECT addressToSymbol(94138803686098) \G ``` ``` text Row 1: ────── addressToSymbol(94138803686098): _ZNK2DB24IAggregateFunctionHelperINS_20AggregateFunctionSumImmNS_24AggregateFunctionSumDataImEEEEE19addBatchSinglePlaceEmPcPPKNS_7IColumnEPNS_5ArenaE ``` 将函数应用于整个堆栈跟踪: ``` sql SELECT arrayStringConcat(arrayMap(x -> addressToSymbol(x), trace), '\n') AS trace_symbols FROM system.trace_log LIMIT 1 \G ``` 该 [arrayMap](higher-order-functions.md#higher_order_functions-array-map) 功能允许处理的每个单独的元素 `trace` 阵列由 `addressToSymbols` 功能。 这种处理的结果，你在看 `trace_symbols` 列的输出。 ``` text Row 1: ────── trace_symbols: _ZNK2DB24IAggregateFunctionHelperINS_20AggregateFunctionSumImmNS_24AggregateFunctionSumDataImEEEEE19addBatchSinglePlaceEmPcPPKNS_7IColumnEPNS_5ArenaE _ZNK2DB10Aggregator21executeWithoutKeyImplERPcmPNS0_28AggregateFunctionInstructionEPNS_5ArenaE _ZN2DB10Aggregator14executeOnBlockESt6vectorIN3COWINS_7IColumnEE13immutable_ptrIS3_EESaIS6_EEmRNS_22AggregatedDataVariantsERS1_IPKS3_SaISC_EERS1_ISE_SaISE_EERb _ZN2DB10Aggregator14executeOnBlockERKNS_5BlockERNS_22AggregatedDataVariantsERSt6vectorIPKNS_7IColumnESaIS9_EERS6_ISB_SaISB_EERb _ZN2DB10Aggregator7executeERKSt10shared_ptrINS_17IBlockInputStreamEERNS_22AggregatedDataVariantsE _ZN2DB27AggregatingBlockInputStream8readImplEv _ZN2DB17IBlockInputStream4readEv _ZN2DB26ExpressionBlockInputStream8readImplEv _ZN2DB17IBlockInputStream4readEv _ZN2DB26ExpressionBlockInputStream8readImplEv _ZN2DB17IBlockInputStream4readEv _ZN2DB28AsynchronousBlockInputStream9calculateEv _ZNSt17_Function_handlerIFvvEZN2DB28AsynchronousBlockInputStream4nextEvEUlvE_E9_M_invokeERKSt9_Any_data _ZN14ThreadPoolImplI20ThreadFromGlobalPoolE6workerESt14_List_iteratorIS0_E _ZZN20ThreadFromGlobalPoolC4IZN14ThreadPoolImplIS_E12scheduleImplIvEET_St8functionIFvvEEiSt8optionalImEEUlvE1_JEEEOS4_DpOT0_ENKUlvE_clEv _ZN14ThreadPoolImplISt6threadE6workerESt14_List_iteratorIS0_E execute_native_thread_routine start_thread clone ``` ## demangle {#demangle} 转换一个符号，您可以使用 [addressToSymbol](#addresstosymbol) 函数到C++函数名。 **语法** ``` sql demangle(symbol) ``` **参数** - `symbol` ([字符串](../../sql-reference/data-types/string.md)) — Symbol from an object file. **返回值** - C++函数的名称。 - 如果符号无效，则为空字符串。 类型: [字符串](../../sql-reference/data-types/string.md). **示例** 启用内省功能: ``` sql SET allow_introspection_functions=1 ``` 从中选择第一个字符串 `trace_log` 系统表: ``` sql SELECT * FROM system.trace_log LIMIT 1 \G ``` ``` text Row 1: ────── event_date: 2019-11-20 event_time: 2019-11-20 16:57:59 revision: 54429 timer_type: Real thread_number: 48 query_id: 724028bf-f550-45aa-910d-2af6212b94ac trace: [94138803686098,94138815010911,94138815096522,94138815101224,94138815102091,94138814222988,94138806823642,94138814457211,94138806823642,94138814457211,94138806823642,94138806795179,94138806796144,94138753770094,94138753771646,94138753760572,94138852407232,140399185266395,140399178045583] ``` 该 `trace` 字段包含采样时的堆栈跟踪。 获取单个地址的函数名称: ``` sql SELECT demangle(addressToSymbol(94138803686098)) \G ``` ``` text Row 1: ────── demangle(addressToSymbol(94138803686098)): DB::IAggregateFunctionHelper > >::addBatchSinglePlace(unsigned long, char*, DB::IColumn const**, DB::Arena*) const ``` 将函数应用于整个堆栈跟踪: ``` sql SELECT arrayStringConcat(arrayMap(x -> demangle(addressToSymbol(x)), trace), '\n') AS trace_functions FROM system.trace_log LIMIT 1 \G ``` 该 [arrayMap](higher-order-functions.md#higher_order_functions-array-map) 功能允许处理的每个单独的元素 `trace` 阵列由 `demangle` 功能。 这种处理的结果，你在看 `trace_functions` 列的输出。 ``` text Row 1: ────── trace_functions: DB::IAggregateFunctionHelper > >::addBatchSinglePlace(unsigned long, char*, DB::IColumn const**, DB::Arena*) const DB::Aggregator::executeWithoutKeyImpl(char*&, unsigned long, DB::Aggregator::AggregateFunctionInstruction*, DB::Arena*) const DB::Aggregator::executeOnBlock(std::vector::immutable_ptr, std::allocator::immutable_ptr > >, unsigned long, DB::AggregatedDataVariants&, std::vector >&, std::vector >, std::allocator > > >&, bool&) DB::Aggregator::executeOnBlock(DB::Block const&, DB::AggregatedDataVariants&, std::vector >&, std::vector >, std::allocator > > >&, bool&) DB::Aggregator::execute(std::shared_ptr const&, DB::AggregatedDataVariants&) DB::AggregatingBlockInputStream::readImpl() DB::IBlockInputStream::read() DB::ExpressionBlockInputStream::readImpl() DB::IBlockInputStream::read() DB::ExpressionBlockInputStream::readImpl() DB::IBlockInputStream::read() DB::AsynchronousBlockInputStream::calculate() std::_Function_handler::_M_invoke(std::_Any_data const&) ThreadPoolImpl::worker(std::_List_iterator) ThreadFromGlobalPool::ThreadFromGlobalPool::scheduleImpl(std::function, int, std::optional)::{lambda()#3}>(ThreadPoolImpl::scheduleImpl(std::function, int, std::optional)::{lambda()#3}&&)::{lambda()#1}::operator()() const ThreadPoolImpl::worker(std::_List_iterator) execute_native_thread_routine start_thread clone ```