[sqlserver] add command/connection timeout

10s default, it shouldn't break any existing check, as it is
a timeout for each command.
[skip ci]
(as it is a Windows check not tested)

checks.d/sqlserver.py

@@ -48,6 +48,7 @@ class SQLServer(AgentCheck):
 
     SOURCE_TYPE_NAME = 'sql server'
     SERVICE_CHECK_NAME = 'sqlserver.can_connect'
+    DEFAULT_COMMAND_TIMEOUT = 10
 
     METRICS = [
         ('sqlserver.buffer.cache_hit_ratio', 'Buffer cache hit ratio', ''),  # RAW_LARGE_FRACTION
@@ -181,8 +182,11 @@ def get_cursor(self, instance):
 
         if conn_key not in self.connections:
             try:
-                conn_str = self._conn_string(instance)
-                conn = adodbapi.connect(conn_str)
+                conn = adodbapi.connect(
+                    self._conn_string(instance),
+                    timeout=int(instance.get('command_timeout',
+                                             self.DEFAULT_COMMAND_TIMEOUT))
+                )
                 self.connections[conn_key] = conn
                 self.service_check(self.SERVICE_CHECK_NAME, AgentCheck.OK, tags=service_check_tags)
             except Exception:

conf.d/sqlserver.yaml.example

@@ -37,6 +37,7 @@ instances:
   - host: HOST,PORT
     username: my_username
     password: my_password
+    # command_timeout: 5 # Optional, timeout for each command run (so for each metric)
     # database: my_database # Optional, defaults to "master"
     tags:
       - optional_tag