added request-source (#2599)

arangod/Agency/AgencyFeature.cpp

@@ -38,6 +38,8 @@ using namespace arangodb::basics;
 using namespace arangodb::options;
 using namespace arangodb::rest;
 
+consensus::Agent* AgencyFeature::AGENT = nullptr;
+
 AgencyFeature::AgencyFeature(application_features::ApplicationServer* server)
     : ApplicationFeature(server, "Agency"),
       _activated(false),
@@ -216,7 +218,6 @@ void AgencyFeature::prepare() {
 }
 
 void AgencyFeature::start() {
-
   if (!isEnabled()) {
     return;
   }
@@ -265,6 +266,8 @@ void AgencyFeature::start() {
       _compactionStepSize, _compactionKeepSize, _supervisionGracePeriod,
       _cmdLineTimings, _maxAppendSize)));
 
+  AGENT = _agent.get();
+
   LOG_TOPIC(DEBUG, Logger::AGENCY) << "Starting agency personality";
   _agent->start();
 
@@ -307,4 +310,6 @@ void AgencyFeature::stop() {
       }
     }
   }
+
+  AGENT = nullptr;
 }

arangod/Agency/AgencyFeature.h

@@ -31,6 +31,9 @@ class Agent;
 }
 
 class AgencyFeature : virtual public application_features::ApplicationFeature {
+ public:
+  static consensus::Agent* AGENT;
+  
  public:
   explicit AgencyFeature(application_features::ApplicationServer* server);
   ~AgencyFeature();
@@ -47,7 +50,6 @@ class AgencyFeature : virtual public application_features::ApplicationFeature {
   bool _activated;
   uint64_t _size;  // agency size (default: 5)
   uint64_t _poolSize;
-  std::string _agentId;
   double _minElectionTimeout;  // min election timeout
   double _maxElectionTimeout;  // max election timeout
   bool _supervision;

arangod/Cluster/ClusterComm.cpp

@@ -22,6 +22,9 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 #include "ClusterComm.h"
+
+#include "Agency/AgencyFeature.h"
+#include "Agency/Agent.h"
 #include "Basics/ConditionLocker.h"
 #include "Basics/HybridLogicalClock.h"
 #include "Basics/StringUtils.h"
@@ -1099,6 +1102,18 @@ std::pair<ClusterCommResult*, HttpRequest*> ClusterComm::prepareRequest(std::str
   headersCopy[StaticStrings::HLCHeader] =
     arangodb::basics::HybridLogicalClock::encodeTimeStamp(timeStamp);
 
+  auto state = ServerState::instance();
+
+  if (state->isCoordinator() || state->isDBServer()) {
+    headersCopy[StaticStrings::ClusterCommSource] = state->getId();
+  } else if (state->isAgent()) {
+    auto agent = AgencyFeature::AGENT;
+
+    if (agent != nullptr) {
+      headersCopy[StaticStrings::ClusterCommSource] = "AGENT-" + agent->id();
+    }
+  }
+
 #ifdef DEBUG_CLUSTER_COMM
 #ifdef ARANGODB_ENABLE_MAINTAINER_MODE
 #if ARANGODB_ENABLE_BACKTRACE

arangod/GeneralServer/HttpCommTask.cpp

@@ -259,8 +259,9 @@ bool HttpCommTask::processRead(double startTime) {
     size_t headerLength = ptr - (_readBuffer.c_str() + _startPosition);
 
     if (headerLength > MaximalHeaderSize) {
-      LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "maximal header size is " << MaximalHeaderSize
-                << ", request header size is " << headerLength;
+      LOG_TOPIC(WARN, arangodb::Logger::FIXME)
+          << "maximal header size is " << MaximalHeaderSize
+          << ", request header size is " << headerLength;
 
       HttpRequest tmpRequest(_connectionInfo, nullptr, 0, _allowMethodOverride);
       // header is too large
@@ -626,6 +627,16 @@ void HttpCommTask::processRequest(std::unique_ptr<HttpRequest> request) {
     }
   }
 
+  // check source
+  std::string const& source =
+      request->header(StaticStrings::ClusterCommSource, found);
+
+  if (found) {
+    LOG_TOPIC(TRACE, Logger::REQUESTS)
+        << "\"http-request-source\",\"" << (void*)this << "\",\""
+        << source << "\"";
+  }
+
   // create a handler and execute
   std::unique_ptr<GeneralResponse> response(
       new HttpResponse(rest::ResponseCode::SERVER_ERROR));

lib/Basics/StaticStrings.cpp

@@ -83,6 +83,7 @@ std::string const StaticStrings::BatchContentType(
     "application/x-arango-batchpart");
 std::string const StaticStrings::CacheControl("cache-control");
 std::string const StaticStrings::Close("Close");
+std::string const StaticStrings::ClusterCommSource("x-arango-source");
 std::string const StaticStrings::Code("code");
 std::string const StaticStrings::Connection("connection");
 std::string const StaticStrings::ContentEncoding("content-encoding");

lib/Basics/StaticStrings.h

@@ -82,6 +82,7 @@ class StaticStrings {
   static std::string const BatchContentType;
   static std::string const CacheControl;
   static std::string const Close;
+  static std::string const ClusterCommSource;
   static std::string const Code;
   static std::string const Connection;
   static std::string const ContentEncoding;