| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| #include "kudu/server/pprof_path_handlers.h" |
| |
| #include <unistd.h> |
| |
| #include <cstdint> |
| #include <cstdlib> |
| #include <fstream> |
| #include <functional> |
| #include <string> |
| #include <unordered_map> |
| #include <utility> |
| #include <vector> |
| |
| #include <gflags/gflags_declare.h> |
| #include <glog/logging.h> |
| #ifdef TCMALLOC_ENABLED |
| #include <gperftools/heap-profiler.h> |
| #include <gperftools/malloc_extension.h> |
| #include <gperftools/profiler.h> |
| #endif |
| |
| #include "kudu/gutil/map-util.h" |
| #include "kudu/gutil/strings/numbers.h" |
| #include "kudu/gutil/strings/split.h" |
| #include "kudu/gutil/strings/stringpiece.h" |
| #include "kudu/gutil/strings/strip.h" |
| #include "kudu/gutil/strings/substitute.h" |
| #include "kudu/gutil/sysinfo.h" |
| #include "kudu/server/webserver.h" |
| #include "kudu/util/env.h" |
| #include "kudu/util/faststring.h" |
| #include "kudu/util/monotime.h" |
| #include "kudu/util/spinlock_profiling.h" |
| #include "kudu/util/status.h" |
| #include "kudu/util/web_callback_registry.h" |
| |
| DECLARE_bool(enable_process_lifetime_heap_profiling); |
| DECLARE_string(heap_profile_path); |
| |
| |
| using std::endl; |
| using std::ifstream; |
| using std::ostringstream; |
| using std::string; |
| using std::vector; |
| |
| // GLog already implements symbolization. Just import their hidden symbol. |
| namespace google { |
| // Symbolizes a program counter. On success, returns true and write the |
| // symbol name to "out". The symbol name is demangled if possible |
| // (supports symbols generated by GCC 3.x or newer). Otherwise, |
| // returns false. |
| bool Symbolize(void *pc, char *out, size_t out_size); |
| } |
| |
| namespace kudu { |
| |
| const int kPprofDefaultSampleSecs = 30; // pprof default sample time in seconds. |
| |
| // pprof asks for the url /pprof/cmdline to figure out what application it's profiling. |
| // The server should respond by sending the executable path. |
| static void PprofCmdLineHandler(const Webserver::WebRequest& /*req*/, |
| Webserver::PrerenderedWebResponse* resp) { |
| string executable_path; |
| Env* env = Env::Default(); |
| WARN_NOT_OK(env->GetExecutablePath(&executable_path), "Failed to get executable path"); |
| resp->output << executable_path; |
| } |
| |
| // pprof asks for the url /pprof/heap to get heap information. This should be implemented |
| // by calling HeapProfileStart(filename), continue to do work, and then, some number of |
| // seconds later, call GetHeapProfile() followed by HeapProfilerStop(). |
| static void PprofHeapHandler(const Webserver::WebRequest& /*req*/, |
| Webserver::PrerenderedWebResponse* resp) { |
| ostringstream* output = &resp->output; |
| #ifndef TCMALLOC_ENABLED |
| *output << "%warn Heap profiling is not available without tcmalloc.\n"; |
| #else |
| // If we've started the process with heap profiling then dump the full profile. |
| if (IsHeapProfilerRunning()) { |
| char* profile = GetHeapProfile(); |
| *output << profile; |
| free(profile); |
| return; |
| } |
| |
| // Otherwise dump the sample. |
| string buf; |
| MallocExtension::instance()->GetHeapSample(&buf); |
| if (buf.find("This heap profile does not have any data") != string::npos) { |
| // If sampling is disabled, tcmalloc prints a nice message with instructions |
| // how to enable it. However, it only describes the environment variable method |
| // and not our own gflag-based method, so we'll replace it with our own message. |
| buf = "%warn\n" |
| "%warn This heap profile does not have any data in it, because\n" |
| "%warn the application was run with heap sampling turned off.\n" |
| "%warn To obtain a heap sample, you must set the environment\n" |
| "%warn variable TCMALLOC_SAMPLE_PARAMETER or the flag\n" |
| "%warn --heap-sample-every-n-bytes to a positive sampling period,\n" |
| "%warn such as 524288.\n" |
| "%warn\n"; |
| } |
| *output << buf; |
| #endif |
| } |
| |
| // pprof asks for the url /pprof/profile?seconds=XX to get cpu-profiling information. |
| // The server should respond by calling ProfilerStart(), continuing to do its work, |
| // and then, XX seconds later, calling ProfilerStop(). |
| static void PprofCpuProfileHandler(const Webserver::WebRequest& req, |
| Webserver::PrerenderedWebResponse* resp) { |
| ostringstream* output = &resp->output; |
| #ifndef TCMALLOC_ENABLED |
| *output << "%warn CPU profiling is not available without tcmalloc.\n"; |
| #else |
| auto it = req.parsed_args.find("seconds"); |
| int seconds = kPprofDefaultSampleSecs; |
| if (it != req.parsed_args.end()) { |
| seconds = atoi(it->second.c_str()); |
| } |
| // Build a temporary file name that is hopefully unique. |
| string tmp_prof_file_name = strings::Substitute("/tmp/kudu_cpu_profile.$0.$1", getpid(), rand()); |
| ProfilerStart(tmp_prof_file_name.c_str()); |
| SleepFor(MonoDelta::FromSeconds(seconds)); |
| ProfilerStop(); |
| ifstream prof_file(tmp_prof_file_name.c_str(), std::ios::in); |
| if (!prof_file.is_open()) { |
| *output << "Unable to open cpu profile: " << tmp_prof_file_name; |
| return; |
| } |
| *output << prof_file.rdbuf(); |
| prof_file.close(); |
| #endif |
| } |
| |
| // pprof asks for the url /pprof/growth to get heap-profiling delta (growth) information. |
| // The server should respond by calling: |
| // MallocExtension::instance()->GetHeapGrowthStacks(&output); |
| static void PprofGrowthHandler(const Webserver::WebRequest& /*req*/, |
| Webserver::PrerenderedWebResponse* resp) { |
| #ifndef TCMALLOC_ENABLED |
| resp->output << "%warn Growth profiling is not available without tcmalloc.\n"; |
| #else |
| string heap_growth_stack; |
| MallocExtension::instance()->GetHeapGrowthStacks(&heap_growth_stack); |
| resp->output << heap_growth_stack; |
| #endif |
| } |
| |
| // Lock contention profiling |
| static void PprofContentionHandler(const Webserver::WebRequest& req, |
| Webserver::PrerenderedWebResponse* resp) { |
| string secs_str = FindWithDefault(req.parsed_args, "seconds", ""); |
| int32_t seconds = ParseLeadingInt32Value(secs_str.c_str(), kPprofDefaultSampleSecs); |
| int64_t discarded_samples = 0; |
| |
| MonoTime end = MonoTime::Now() + MonoDelta::FromSeconds(seconds); |
| ostringstream profile; |
| StartSynchronizationProfiling(); |
| while (MonoTime::Now() < end) { |
| SleepFor(MonoDelta::FromMilliseconds(500)); |
| FlushSynchronizationProfile(&profile, &discarded_samples); |
| } |
| StopSynchronizationProfiling(); |
| FlushSynchronizationProfile(&profile, &discarded_samples); |
| |
| ostringstream* output = &resp->output; |
| *output << "--- contention:" << endl; |
| *output << "sampling period = 1" << endl; |
| *output << "cycles/second = " << static_cast<int64_t>(base::CyclesPerSecond()) << endl; |
| // pprof itself ignores this value, but we can at least look at it in the textual |
| // output. |
| *output << "discarded samples = " << discarded_samples << std::endl; |
| *output << profile.str(); |
| |
| #if defined(__linux__) |
| // procfs only exists on Linux. |
| faststring maps; |
| ReadFileToString(Env::Default(), "/proc/self/maps", &maps); |
| *output << "--- Memory map: ---" << endl; |
| *output << maps.ToString(); |
| #endif // defined(__linux__) |
| } |
| |
| |
| // pprof asks for the url /pprof/symbol to map from hex addresses to variable names. |
| // When the server receives a GET request for /pprof/symbol, it should return a line |
| // formatted like: num_symbols: ### |
| // where ### is the number of symbols found in the binary. For now, the only important |
| // distinction is whether the value is 0, which it is for executables that lack debug |
| // information, or not-0). |
| // |
| // In addition to the GET request for this url, the server must accept POST requests. |
| // This means that after the HTTP headers, pprof will pass in a list of hex addresses |
| // connected by +, like: |
| // curl -d '0x0824d061+0x0824d1cf' http://remote_host:80/pprof/symbol |
| // The server should read the POST data, which will be in one line, and for each hex value |
| // should write one line of output to the output stream, like so: |
| // <hex address><tab><function name> |
| // For instance: |
| // 0x08b2dabd _Update |
| static void PprofSymbolHandler(const Webserver::WebRequest& req, |
| Webserver::PrerenderedWebResponse* resp) { |
| if (req.request_method == "GET") { |
| // Per the above comment, pprof doesn't expect to know the actual number of symbols. |
| // Any non-zero value indicates that we support symbol lookup. |
| resp->output << "num_symbols: 1"; |
| return; |
| } |
| |
| int missing_symbols = 0; |
| int invalid_addrs = 0; |
| |
| // Symbolization request. |
| vector<StringPiece> pieces = strings::Split(req.post_data, "+"); |
| for (StringPiece p : pieces) { |
| string hex_addr; |
| if (!TryStripPrefixString(p, "0x", &hex_addr)) { |
| invalid_addrs++; |
| continue; |
| } |
| uint64_t addr; |
| if (!safe_strtou64_base(hex_addr.c_str(), &addr, 16)) { |
| invalid_addrs++; |
| continue; |
| } |
| char symbol_buf[1024]; |
| if (google::Symbolize(reinterpret_cast<void*>(addr), symbol_buf, sizeof(symbol_buf))) { |
| resp->output << p << "\t" << symbol_buf << std::endl; |
| } else { |
| missing_symbols++; |
| } |
| } |
| |
| LOG(INFO) << strings::Substitute( |
| "Handled request for /pprof/symbol: requested=$0 invalid_addrs=$1 missing=$2", |
| pieces.size(), invalid_addrs, missing_symbols); |
| } |
| |
| void AddPprofPathHandlers(Webserver* webserver) { |
| // Path handlers for remote pprof profiling. For information see: |
| // https://gperftools.googlecode.com/svn/trunk/doc/pprof_remote_servers.html |
| webserver->RegisterPrerenderedPathHandler("/pprof/cmdline", "", PprofCmdLineHandler, |
| false, false); |
| webserver->RegisterPrerenderedPathHandler("/pprof/heap", "", PprofHeapHandler, false, false); |
| webserver->RegisterPrerenderedPathHandler("/pprof/growth", "", PprofGrowthHandler, false, false); |
| webserver->RegisterPrerenderedPathHandler("/pprof/profile", "", PprofCpuProfileHandler, |
| false, false); |
| webserver->RegisterPrerenderedPathHandler("/pprof/symbol", "", PprofSymbolHandler, false, false); |
| webserver->RegisterPrerenderedPathHandler("/pprof/contention", "", PprofContentionHandler, |
| false, false); |
| } |
| |
| } // namespace kudu |