doc: update doc on adding kill statement support (#1515)

* update doc on adding kill statement support Signed-off-by: Harshit Gangal <harshit@planetscale.com> * Update content/en/docs/18.0/reference/compatibility/mysql-compatibility.md Co-authored-by: Deepthi Sigireddi <deepthi@planetscale.com> Signed-off-by: Harshit Gangal <harshit@planetscale.com> * Update content/en/docs/18.0/reference/compatibility/mysql-compatibility.md Co-authored-by: Deepthi Sigireddi <deepthi@planetscale.com> Signed-off-by: Harshit Gangal <harshit@planetscale.com> * updated vtgate program page Signed-off-by: Harshit Gangal <harshit@planetscale.com> * more improved version Signed-off-by: Harshit Gangal <harshit@planetscale.com> * tagged rfc for limitation reference Signed-off-by: Harshit Gangal <harshit@planetscale.com> --------- Signed-off-by: Harshit Gangal <harshit@planetscale.com> Co-authored-by: Deepthi Sigireddi <deepthi@planetscale.com>
vitessio · Jul 11, 2023 · 31ef43f · 31ef43f
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diff --git a/content/en/docs/18.0/reference/compatibility/mysql-compatibility.md b/content/en/docs/18.0/reference/compatibility/mysql-compatibility.md
@@ -125,16 +125,26 @@ Vitess does not yet support Window Functions or Common Table Expressions.
 
 ### Killing running queries
 
-Vitess does not yet support killing running queries via the `KILL` command through VTGate.
-Currently, there exists a comment directive [QUERY_TIMEOUT_MS](../../../user-guides/configuration-advanced/comment-directives/#query-timeouts-query_timeout_ms) that can be set to reduce the query timeout which will ensure that the query either return result or abort within that time.
+In v18, Vitess introduced the ability to terminate running queries using the [`KILL` command](https://dev.mysql.com/doc/refman/8.0/en/kill.html) through VTGate.
+To execute a "kill connection" or "kill query" statement, the client needs to establish a new connection.
+This behavior is similar to when a user on the MySQL shell client terminates a command by pressing ctrl+c.
 
-Vitess does have strict query timeouts for OLTP workloads (see below). If you need to kill a query, you can connect to the underlying MySQL shard instance and run `KILL` from there.
+The [RFC](https://github.com/vitessio/vitess/issues/13438) highlights the current limitation of the `Kill statement` support. 
+
+Alternatively, 
+- [query_timeout_ms](../../../user-guides/configuration-advanced/comment-directives/#query-timeouts-query_timeout_ms) query comment directive can be set to define a query timeout. This ensures that the query either returns a result or aborts within the specified time.
+- [mysql_server_query_timeout](../../programs/vtgate/) command-line flag can be set on VTGate to establish a default timeout.
+
+Vitess does have strict query timeouts for OLTP workloads (see below).
 
 ### Workload
 
-By default, Vitess sets some intentional restrictions on the execution time and number of rows that a query can return. This default workload mode is called `OLTP`. This can be disabled by setting the workload to `OLAP`:
+By default, Vitess applies specific limitations on the execution time and the number of rows a query can return.
+These limitations can be modified by adjusting the parameters like `queryserver-config-query-timeout`, `queryserver-config-transaction-timeout` and more in [vttablet](../../programs/vttablet/).
+This default workload mode is referred as `OLTP`. This can be disabled by switching to `OLAP` mode by executing the following SQL statement:
+
 ```sql
-SET workload='olap'
+set workload = olap;
 ```
 
 ### SELECT ... INTO Statement

diff --git a/content/en/docs/18.0/reference/programs/vtgate.md b/content/en/docs/18.0/reference/programs/vtgate.md
@@ -32,6 +32,7 @@ The following global options apply to `vtgate`:
 
 | Name                                                             | Type                  | Definition                                                                                                                                                                                                                                                             |
 |:-----------------------------------------------------------------|:----------------------|:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| --allow-kill-statement                                           | Boolean               | Allows the execution of kill statement                                                                                                                                                                                                                                 |                                                                                                                                    
 | --allowed_tablet_types                                           | Strings               | Specifies the tablet types this vtgate is allowed to route queries to. Should be provided as a comma-separated set of tablet types.                                                                                                                                    |                                                                                                                                    
 | --alsologtostderr                                                | Boolean               | log to standard error as well as files                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 
 | --buffer_drain_concurrency                                       | Int                   | Maximum number of requests retried simultaneously. More concurrency will increase the load on the PRIMARY vttablet when draining the buffer. (default 1)                                                                                                               |