HDFS-10595: libhdfs++: deconflate client name and client id

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/util.cc

@@ -21,6 +21,10 @@
 
 #include <google/protobuf/io/zero_copy_stream_impl_lite.h>
 #include <exception>
+#include <sstream>
+#include <iostream>
+#include <iomanip>
+#include <thread>
 
 namespace hdfs {
 
@@ -56,25 +60,17 @@ std::string SerializeDelimitedProtobufMessage(const ::google::protobuf::MessageL
 
 
 std::string GetRandomClientName() {
-  /**
-   *  The server is requesting a 16-byte UUID:
-   *  https://github.com/c9n/hadoop/blob/master/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ClientId.java
-   *
-   *  This function generates a 16-byte UUID (version 4):
-   *  https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
-   **/
-  unsigned char buf[16];
-  RAND_pseudo_bytes(buf, sizeof(buf));
+  std::vector<unsigned char>buf(8);
+  RAND_pseudo_bytes(&buf[0], 8);
 
-  //clear the first four bits of byte 6 then set the second bit
-  buf[6] = (buf[6] & 0x0f) | 0x40;
+  std::ostringstream oss;
+  oss << "DFSClient_"  << getpid() <<  "_" <<
+          std::this_thread::get_id() << "_" <<
+          std::setw(2) << std::hex << std::uppercase << std::setfill('0');
+  for (unsigned char b: buf)
+    oss << static_cast<unsigned>(b);
 
-  //clear the second bit of byte 8 and set the first bit
-  buf[8] = (buf[8] & 0xbf) | 0x80;
-
-  std::stringstream ss;
-  ss << std::string(reinterpret_cast<char *>(buf), sizeof(buf));
-  return ss.str();
+  return oss.str();
 }
 
 std::string SafeDisconnect(asio::ip::tcp::socket *sock) {

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_connection.cc

@@ -102,7 +102,7 @@ static void SetRequestHeader(LockFreeRpcEngine *engine, int call_id,
   rpc_header->set_callid(call_id);
   if (retry_count != kNoRetry)
     rpc_header->set_retrycount(retry_count);
-  rpc_header->set_clientid(engine->client_name());
+  rpc_header->set_clientid(engine->client_id());
 
   req_header->set_methodname(method_name);
   req_header->set_declaringclassprotocolname(engine->protocol_name());

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_engine.cc

@@ -145,6 +145,7 @@ RpcEngine::RpcEngine(::asio::io_service *io_service, const Options &options,
     : io_service_(io_service),
       options_(options),
       client_name_(client_name),
+      client_id_(getRandomClientId()),
       protocol_name_(protocol_name),
       protocol_version_(protocol_version),
       call_id_(0),
@@ -206,6 +207,28 @@ std::unique_ptr<const RetryPolicy> RpcEngine::MakeRetryPolicy(const Options &opt
   }
 }
 
+std::string RpcEngine::getRandomClientId()
+{
+  /**
+   *  The server is requesting a 16-byte UUID:
+   *  https://github.com/c9n/hadoop/blob/master/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ClientId.java
+   *
+   *  This function generates a 16-byte UUID (version 4):
+   *  https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
+   **/
+  std::vector<unsigned char>buf(16);
+  RAND_pseudo_bytes(&buf[0], buf.size());
+
+  //clear the first four bits of byte 6 then set the second bit
+  buf[6] = (buf[6] & 0x0f) | 0x40;
+
+  //clear the second bit of byte 8 and set the first bit
+  buf[8] = (buf[8] & 0xbf) | 0x80;
+  return std::string(reinterpret_cast<const char*>(&buf[0]), buf.size());
+}
+
+
+
 void RpcEngine::TEST_SetRpcConnection(std::shared_ptr<RpcConnection> conn) {
   conn_ = conn;
   retry_policy_ = std::move(MakeRetryPolicy(options_));

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_engine.h

@@ -269,6 +269,7 @@ public:
   virtual int NextCallId() = 0;
 
   virtual const std::string &client_name() const = 0;
+  virtual const std::string &client_id() const = 0;
   virtual const std::string &user_name() const = 0;
   virtual const std::string &protocol_name() const = 0;
   virtual int protocol_version() const = 0;
@@ -380,6 +381,7 @@ class RpcEngine : public LockFreeRpcEngine {
   std::unique_ptr<const RetryPolicy> TEST_GenerateRetryPolicyUsingOptions();
 
   const std::string &client_name() const override { return client_name_; }
+  const std::string &client_id() const override { return client_id_; }
   const std::string &user_name() const override { return auth_info_.getUser(); }
   const std::string &protocol_name() const override { return protocol_name_; }
   int protocol_version() const override { return protocol_version_; }
@@ -394,6 +396,8 @@ protected:
   virtual std::shared_ptr<RpcConnection> NewConnection();
   virtual std::unique_ptr<const RetryPolicy> MakeRetryPolicy(const Options &options);
 
+  static std::string getRandomClientId();
+
   // Remember all of the last endpoints in case we need to reconnect and retry
   std::vector<::asio::ip::tcp::endpoint> last_endpoints_;
 
@@ -401,6 +405,7 @@ private:
   ::asio::io_service * const io_service_;
   const Options options_;
   const std::string client_name_;
+  const std::string client_id_;
   const std::string protocol_name_;
   const int protocol_version_;
   std::unique_ptr<const RetryPolicy> retry_policy_; //null --> no retry