Add queue_flush_size option

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

plugins/outputs/clickhouse/sample.conf

@@ -27,13 +27,18 @@
     ## Table name prefix
     # table_prefix = "telegraf"
 
-  ## Initial metric queue size, resizes automatically if the queue becomes too large
+  ## Initial metric queue size
+  ## Queue resizes automatically if the queue becomes too large.
   # queue_initial_size = 100000
 
-  ## Maximum queue size, 0 means unlimited.
+  ## Maximum queue size, 0 means unlimited
   ## If the queue reaches this size, new writes will be dropped until it drains.
   # queue_max_size = 0
 
+  ## Queue flush size, 0 means unlimited
+  ## The flush interval will not be reset if the queue is larger than this.
+  # queue_flush_size = 0
+
   ## Flush interval for the metric queue
   ## The agent waits until N seconds have passed without any writes before flushing metrics to ClickHouse.
   # queue_flush_interval = "1"