From a035c91fa629f77ba7af54bf984bc4211fbcf03c Mon Sep 17 00:00:00 2001
From: Dapeng Huang <7xerocha@gmail.com>
Date: Fri, 26 Jan 2018 10:22:30 +0800
Subject: [PATCH] add doc for session_track_trx_state and refactor little

---
 .gitignore                                          |  1 +
 .../Getting-Started/Configuration-Guide.md          | 13 +++++++++++++
 server/modules/protocol/MySQL/mysql_common.cc       |  6 +++---
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index d3f5d2e19..ecfc3032c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -52,6 +52,7 @@ CMakeFiles/*
 */*/*/*/CMakeFiles/*
 Makefile
 /.DS_Store
+.DS_Store
 
 # Netbeans Project files
 nbproject/
diff --git a/Documentation/Getting-Started/Configuration-Guide.md b/Documentation/Getting-Started/Configuration-Guide.md
index 3609f404b..e12058d50 100644
--- a/Documentation/Getting-Started/Configuration-Guide.md
+++ b/Documentation/Getting-Started/Configuration-Guide.md
@@ -1063,6 +1063,19 @@ seconds. The interval is incremented until the value of `max_retry_interval` is
 reached at which point the listener attempts to bind to the interface every
 `max_retry_interval` seconds.
 
+#### `session_track_trx_state`
+
+Enable or disable getting session transation state via session track mechanism. This
+parameter takes a boolean value. Default False.
+
+Get current session transaction state from server side will be more accurate.
+Minimum Server version Mariadb 10.3 or MySQL 5.7 is needed and following server
+config is also needed.
+  ```
+  session_track_state_change = ON
+  session_track_transaction_info = CHARACTERISTICS
+  ```
+
 ### Server
 
 Server sections are used to define the backend database servers that can be
diff --git a/server/modules/protocol/MySQL/mysql_common.cc b/server/modules/protocol/MySQL/mysql_common.cc
index 8ddc4b818..33a567c6c 100644
--- a/server/modules/protocol/MySQL/mysql_common.cc
+++ b/server/modules/protocol/MySQL/mysql_common.cc
@@ -1857,7 +1857,7 @@ void mxs_mysql_get_session_track_info(GWBUF *buff, MySQLProtocol *proto)
     {
         while (gwbuf_copy_data(buff, offset, MYSQL_HEADER_LEN + 1, header_and_command) == (MYSQL_HEADER_LEN + 1))
         {
-            size_t packet_len = gw_mysql_get_byte3(header_and_command);
+            size_t packet_len = gw_mysql_get_byte3(header_and_command) + MYSQL_HEADER_LEN;
             uint8_t cmd = header_and_command[MYSQL_COM_OFFSET];
 
             if (packet_len > MYSQL_OK_PACKET_MIN_LEN &&
@@ -1865,7 +1865,7 @@ void mxs_mysql_get_session_track_info(GWBUF *buff, MySQLProtocol *proto)
                 (proto->num_eof_packets % 2) == 0)
             {
                 buff->gwbuf_type |= GWBUF_TYPE_REPLY_OK;
-                mxs_mysql_parse_ok_packet(buff, offset, packet_len + MYSQL_HEADER_LEN);
+                mxs_mysql_parse_ok_packet(buff, offset, packet_len);
             }
 
             if ((proto->current_command == MXS_COM_QUERY ||
@@ -1875,7 +1875,7 @@ void mxs_mysql_get_session_track_info(GWBUF *buff, MySQLProtocol *proto)
             {
                 proto->num_eof_packets++;
             }
-            offset += (packet_len + MYSQL_HEADER_LEN);
+            offset += packet_len;
         }
     }
 }