BUG#13987 Cluster: Loss of data nodes can cause high CPU usage from ndb_mgmd

smaller patch for 5.0.

complete patch going to 5.1 due to more intrusiveness for 'list sessions' etc


ndb/include/mgmapi/mgmapi.h:
  add internal get_fd to use in test
ndb/include/util/InputStream.hpp:
  - add this weird startover member to SocketInputStream
      - this helps work out if we've read a newline yet and should start inserting
           into buffer from the start
ndb/src/common/util/InputStream.cpp:
  remove evil, add more.
  
  keep track internally we've retrieved a newline yet (m_startover)
ndb/src/common/util/Parser.cpp:
  change way detecting of NoLine
  
  remove some trailing whitespace that was uglying the place up a bit
ndb/src/common/util/socket_io.cpp:
  Always retrieve data from the OS so that we instantly get EOF on disconnect
  and don't end up spinning looking for a newline.
ndb/src/mgmapi/mgmapi.cpp:
  add internal ndb_mgm_get_fd() for internal testing
  
  handle 'node status' a bit better
ndb/test/ndbapi/testMgm.cpp:
  Add test for MgmApiSession disconnection (mgmd at 100%)
  
  not fully automated due to smaller patch for 5.0
  
  will be complete in 5.1

1 files changed, 15 insertions, 11 deletions

diff --git a/ndb/src/mgmapi/mgmapi.cpp b/ndb/src/mgmapi/mgmapi.cpp
index 9bf19dda3a4..12222f25eb8 100644
--- a/ndb/src/mgmapi/mgmapi.cpp
+++ b/ndb/src/mgmapi/mgmapi.cpp
@@ -503,6 +503,18 @@ ndb_mgm_connect(NdbMgmHandle handle, int no_retries,
 }
 
 /**
+ * Only used for low level testing
+ * Never to be used by end user.
+ * Or anybody who doesn't know exactly what they're doing.
+ */
+extern "C"
+int
+ndb_mgm_get_fd(NdbMgmHandle handle)
+{
+  return handle->socket;
+}
+
+/**
  * Disconnect from a mgm server
  */
 extern "C"
@@ -692,22 +704,16 @@ ndb_mgm_get_status(NdbMgmHandle handle)
     SET_ERROR(handle, NDB_MGM_ILLEGAL_SERVER_REPLY, "Probably disconnected");
     return NULL;
   }
-  if(buf[strlen(buf)-1] == '\n')
-    buf[strlen(buf)-1] = '\0';
-
-  if(strcmp("node status", buf) != 0) {
+  if(strcmp("node status\n", buf) != 0) {
     SET_ERROR(handle, NDB_MGM_ILLEGAL_NODE_STATUS, buf);
     return NULL;
   }
-
   if(!in.gets(buf, sizeof(buf)))
   {
     SET_ERROR(handle, NDB_MGM_ILLEGAL_SERVER_REPLY, "Probably disconnected");
     return NULL;
   }
-  if(buf[strlen(buf)-1] == '\n')
-    buf[strlen(buf)-1] = '\0';
-  
+
   BaseString tmp(buf);
   Vector<BaseString> split;
   tmp.split(split, ":");
@@ -715,7 +721,7 @@ ndb_mgm_get_status(NdbMgmHandle handle)
     SET_ERROR(handle, NDB_MGM_ILLEGAL_NODE_STATUS, buf);
     return NULL;
   }
- 
+
   if(!(split[0].trim() == "nodes")){
     SET_ERROR(handle, NDB_MGM_ILLEGAL_NODE_STATUS, buf);
     return NULL;
@@ -2280,7 +2286,6 @@ ndb_mgm_check_connection(NdbMgmHandle handle){
   SocketOutputStream out(handle->socket);
   SocketInputStream in(handle->socket, handle->read_timeout);
   char buf[32];
-
   if (out.println("check connection"))
     goto ndb_mgm_check_connection_error;
 
@@ -2490,7 +2495,6 @@ int ndb_mgm_end_session(NdbMgmHandle handle)
 
   SocketInputStream in(handle->socket, handle->read_timeout);
   char buf[32];
-
   in.gets(buf, sizeof(buf));
 
   DBUG_RETURN(0);