Add queue mechanism

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

plugins/outputs/clickhouse/sample.conf

@@ -1,11 +1,43 @@
 # Save metrics to an SQL Database
-[[outputs.sql]]
+[[outputs.clickhouse]]
   ## Data source name
-  # data_source_name = ""
+  data_source_name = ""
 
   ## Initialization SQL
   # init_sql = ""
 
+  ## Timestamp column name
+  # timestamp_column = "timestamp"
+
+  ## Default TTL for data in the table (use ClickHouse syntax)
+  ttl = "3 MONTH"
+
+  ## Table operation mode
+  ## Set to "single" to create a single table for all metrics.
+  ## Set to "multi" to create a new table for each metric.
+  # table_mode = "multi"
+
+  ## Single table configuration
+  # [outputs.clickhouse.single_table]
+    ## Table name
+    # table_name = "telegraf"
+
+  ## Multi table configuration
+  # [outputs.clickhouse.multi_table]
+    ## Table name prefix
+    # table_prefix = "telegraf"
+
+  ## Initial metric queue size, resizes automatically if the queue becomes too large
+  # queue_size = 100000
+
+  ## Maximum queue size, 0 means unlimited.
+  ## If the queue reaches this size, new writes will be dropped until it drains.
+  # queue_limit = 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 = "5"
+
   ## Maximum amount of time a connection may be idle. "0s" means connections are
   ## never closed due to idle time.
   # connection_max_idle_time = "0s"