added environmentfeature

arangod/RestServer/arangod.cpp

@@ -30,6 +30,7 @@
 #include "Agency/AgencyFeature.h"
 #include "ApplicationFeatures/ConfigFeature.h"
 #include "ApplicationFeatures/DaemonFeature.h"
+#include "ApplicationFeatures/EnvironmentFeature.h"
 #include "ApplicationFeatures/GreetingsFeature.h"
 #include "ApplicationFeatures/JemallocFeature.h"
 #include "ApplicationFeatures/LanguageFeature.h"
@@ -144,6 +145,7 @@ static int runServer(int argc, char** argv, ArangoGlobalContext &context) {
     server.addFeature(new DatabasePathFeature(&server));
     server.addFeature(new EndpointFeature(&server));
     server.addFeature(new EngineSelectorFeature(&server));
+    server.addFeature(new EnvironmentFeature(&server));
     server.addFeature(new FeatureCacheFeature(&server));
     server.addFeature(new FileDescriptorsFeature(&server));
     server.addFeature(new FoxxQueuesFeature(&server));

lib/ApplicationFeatures/EnvironmentFeature.cpp

@@ -0,0 +1,105 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
+///
+/// Licensed 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.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Jan Steemann
+////////////////////////////////////////////////////////////////////////////////
+
+#include "EnvironmentFeature.h"
+#include "Basics/FileUtils.h"
+#include "Basics/StringUtils.h"
+#include "Logger/Logger.h"
+
+using namespace arangodb;
+using namespace arangodb::basics;
+
+EnvironmentFeature::EnvironmentFeature(
+    application_features::ApplicationServer* server)
+    : ApplicationFeature(server, "Environment") {
+  setOptional(false);
+  requiresElevatedPrivileges(false);
+  startsAfter("Greetings");
+  startsAfter("Logger");
+}
+
+void EnvironmentFeature::prepare() {
+#if 0
+  if (sizeof(void*) == 4) {
+    // 32 bit build
+    LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "this is a 32 bit build of ArangoDB. "
+               << "it is recommended to run a 64 bit build instead because it can "
+               << "address significantly bigger regions of memory.";
+  }
+
+#ifdef __linux__
+  try {
+    std::string value = basics::FileUtils::slurp("/proc/sys/vm/overcommit_memory");
+    uint64_t v = basics::StringUtils::uint64(value);
+    if (v == 2) {
+      // from https://www.kernel.org/doc/Documentation/sysctl/vm.txt:
+      //
+      //   When this flag is 0, the kernel attempts to estimate the amount
+      //   of free memory left when userspace requests more memory.
+      //   When this flag is 1, the kernel pretends there is always enough
+      //   memory until it actually runs out.
+      //   When this flag is 2, the kernel uses a "never overcommit"
+      //   policy that attempts to prevent any overcommit of memory.
+      LOG_TOPIC(WARN, Logger::FIXME) << "/proc/sys/vm/overcommit_memory is set to '" 
+                 << v << "'. it is recommended to set it to a value of 0 or 1";
+    }
+  } catch (...) {
+    // file not found or value not convertible into integer
+  }
+  
+  try {
+    std::string value = basics::FileUtils::slurp("/proc/sys/vm/zone_reclaim_mode");
+    uint64_t v = basics::StringUtils::uint64(value);
+    if (v != 0) {
+      // from https://www.kernel.org/doc/Documentation/sysctl/vm.txt:
+      //
+      //    This is value ORed together of
+      //    1 = Zone reclaim on
+      //    2 = Zone reclaim writes dirty pages out
+      //    4 =  Zone reclaim swaps pages
+      // 
+      // https://www.poempelfox.de/blog/2010/03/19/
+      LOG_TOPIC(WARN, Logger::FIXME) << "/proc/sys/vm/zone_reclaim_mode is set to '" 
+                 << v << "'. it is recommended to set it to a value of 0";
+    }
+  } catch (...) {
+    // file not found or value not convertible into integer
+  }
+
+  try {
+    std::string value = basics::FileUtils::slurp("/sys/kernel/mm/transparent_hugepage/enabled");
+    size_t start = value.find('[');
+    size_t end = value.find(']');
+    if (start != std::string::npos && end != std::string::npos && start < end && end - start >= 4) {
+      value = value.substr(start + 1, end - start - 1);
+      if (value == "always") {
+        LOG_TOPIC(WARN, Logger::FIXME) << "/sys/kernel/mm/transparent_hugepage/enabled is set to '" 
+                   << value << "'. it is recommended to set it to a value of 'never' or 'madvise'";
+      }
+    }
+  } catch (...) {
+    // file not found
+  }
+#endif
+
+#endif
+}

lib/ApplicationFeatures/EnvironmentFeature.h

@@ -0,0 +1,38 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
+///
+/// Licensed 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.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Jan Steemann
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef ARANGODB_APPLICATION_FEATURES_ENVIRONMENT_FEATURE_H
+#define ARANGODB_APPLICATION_FEATURES_ENVIRONMENT_FEATURE_H 1
+
+#include "ApplicationFeatures/ApplicationFeature.h"
+
+namespace arangodb {
+class EnvironmentFeature final : public application_features::ApplicationFeature {
+ public:
+  explicit EnvironmentFeature(application_features::ApplicationServer* server);
+
+ public:
+  void prepare() override final;
+};
+}
+
+#endif

lib/ApplicationFeatures/JemallocFeature.cpp

@@ -28,8 +28,6 @@
 #include "Logger/Logger.h"
 #include "ProgramOptions/ProgramOptions.h"
 
-#include <iostream>
-
 using namespace arangodb;
 using namespace arangodb::basics;
 using namespace arangodb::options;

lib/CMakeLists.txt

@@ -110,6 +110,7 @@ add_library(${LIB_ARANGO} STATIC
   ApplicationFeatures/ApplicationFeature.cpp
   ApplicationFeatures/ApplicationServer.cpp
   ApplicationFeatures/ConfigFeature.cpp
+  ApplicationFeatures/EnvironmentFeature.cpp
   ApplicationFeatures/GreetingsFeature.cpp
   ApplicationFeatures/JemallocFeature.cpp
   ApplicationFeatures/LanguageFeature.cpp