*: refine syncer check list (pingcap#119)

Author: csuzhangxc

.github/ISSUE_TEMPLATE/syncer-support.md

@@ -6,6 +6,34 @@ about: "Requesting support for syncer Tool"
 
 ## syncer Support
 
+Before submitting your issue, please check the requirements list below (all need to be met):
+
+1. Upstream MySQL version (execute `SELECT @@version;` in a MySQL client)
+    - MySQL: 5.6 <= version < 5.7
+    - MariaDB: version >= 10.1.2 
+2. Upstream MySQL `server_id` (execute `SHOW VARIABLES LIKE 'server_id';` in a MySQL client)
+    - 0 < server_id < 4294967295
+    - also needs to be unique
+3. Upstream MySQL user privileges
+    - SELECT
+    - REPLICATION SLAVE
+    - REPLICATION CLIENT
+4. Downstream TiDB user privileges
+    - SELECT
+    - INSERT
+    - UPDATE
+    - DELETE
+    - CREATE
+    - DROP
+    - ALTER
+    - INDEX
+5. Upstream MySQL variables for binlog
+    - `SHOW GLOBAL VARIABLES LIKE 'log_bin';`: `ON`
+    - `SHOW GLOBAL VARIABLES LIKE 'binlog_format';`: `ROW`  
+        if you start to sync from an older binlog pos, you must ensure the `binlog_format` from that pos is also `ROW`.
+    - for MySQL >= 5.6.2 or MariaDB >= 10.1.6, `SHOW GLOBAL VARIABLES LIKE 'binlog_row_image';`: `FULL`
+
+
 Please describe your problem here:
 
 >
@@ -22,18 +50,36 @@ Additionally, please provide the following info before submitting your issue. Th
         (paste syncer version here)
         ```
 
-    - [ ] TiDB cluster version (execute `SELECT tidb_version();` in a MySQL client):
+    - [ ] Upstream MySQL server version (execute `SELECT @@version;` in a MySQL client):
+
+        ```
+        (paste upstream MySQL server version here)
+        ```
+
+    - [ ] Downstream TiDB cluster version (execute `SELECT tidb_version();` in a MySQL client):
+
+        ```
+        (paste downstream TiDB cluster version here)
+        ```
+
+    - [ ] Upstream MySQL sql_mode (execute `SELECT @@sql_mode;` in a MySQL client):
+
+        ```
+        (paste MySQL sql_mode here)
+        ```
+
+    - [ ] Downstream TiDB sql_mode (execute `SELECT @@sql_mode;` in a MySQL client):
 
         ```
-        (paste TiDB cluster version here)
+        (paste TiDB sql_mode here)
         ```
 
     - [ ] How did you deploy syncer?
 
         ```
         ```
 
-    - [ ] Other interesting information (system version, hardware config, etc):
+    - [ ] Other interesting information (table schema, system version, hardware config, etc):
 
         >
         >
@@ -48,4 +94,5 @@ Additionally, please provide the following info before submitting your issue. Th
 3. Common issues
     - [ ] Is the `worker-count` set to a reasonable value (suggest-32)?
     - [ ] Is the `batch` set to a reasonable value (suggest 100-1000)?
-    - [ ] Is the downstream server MySQL and does not use the `utf8mb4` charset (syncer only allows the downstream server's charset to be `utf8mb4`)?
+    - [ ] Is the downstream server MySQL and does not use the `utf8mb4` charset (syncer only allows the downstream server's charset to be `utf8mb4`)?
+    - [ ] Do not some tables have primary/unique keys and slow synchronization? Syncer is not friendly for tables don't have priamry/unique key.