[Doc] clarified the usage of and settings

CHANGELOG.md

@@ -1,3 +1,6 @@
+## Unreleased
+ - [DOC] clarified the usage of `jdbc_validation_timeout` and `connection_retry_attempts_wait_time` settings. [#169](https://github.com/logstash-plugins/logstash-integration-jdbc/pull/169)
+
 ## 5.4.10
  - Adds retry mechanism when checkout Derby from SVN repository [#158](https://github.com/logstash-plugins/logstash-integration-jdbc/pull/158)
  - [DOC] add known limitations and settings for connection issue [#167](https://github.com/logstash-plugins/logstash-integration-jdbc/pull/167)

docs/filter-jdbc_streaming.asciidoc

@@ -213,6 +213,7 @@ Validate connection before use.
 
 Connection pool configuration.
 How often to validate a connection (in seconds).
+Validation is done only when a connection is borrowed from the pool and not done actively while lays in the pool.
 
 [id="plugins-{type}s-{plugin}-parameters"]
 ===== `parameters`

docs/input-jdbc.asciidoc

@@ -294,7 +294,7 @@ Maximum number of times to try connecting to database
   * Value type is <<number,number>>
   * Default value is `0.5`
 
-Number of seconds to sleep between connection attempts
+Number of seconds to sleep between connection pool creation attempts. Used only during the registration of the plugin.
 
 [id="plugins-{type}s-{plugin}-jdbc_connection_string"]
 ===== `jdbc_connection_string`
@@ -508,7 +508,8 @@ Validate connection before use.
   * Default value is `3600`
 
 Connection pool configuration.
-How often to validate a connection (in seconds)
+How often to validate a connection (in seconds).
+Validation is done only when a connection is borrowed from the pool and not done actively while lays in the pool.
 
 [id="plugins-{type}s-{plugin}-last_run_metadata_path"]
 ===== `last_run_metadata_path`

lib/logstash/plugin_mixins/jdbc/jdbc.rb

@@ -69,7 +69,8 @@ def setup_jdbc_config
       config :jdbc_validate_connection, :validate => :boolean, :default => false
 
       # Connection pool configuration.
-      # How often to validate a connection (in seconds)
+      # How often to validate a connection (in seconds).
+      # Validation is done only when a connection is borrowed from the pool and not done actively while lays in the pool.
       config :jdbc_validation_timeout, :validate => :number, :default => 3600
 
       # Connection pool configuration.
@@ -101,7 +102,7 @@ def setup_jdbc_config
 
       # Maximum number of times to try connecting to database
       config :connection_retry_attempts, :validate => :number, :default => 1
-      # Number of seconds to sleep between connection attempts
+      # Number of seconds to sleep between connection pool creation attempts. Used only during the registration of the plugin.
       config :connection_retry_attempts_wait_time, :validate => :number, :default => 0.5
 
       # Maximum number of times to try running statement

lib/logstash/plugin_mixins/jdbc_streaming.rb

@@ -51,7 +51,8 @@ def setup_jdbc_config
     config :jdbc_validate_connection, :validate => :boolean, :default => false
 
     # Connection pool configuration.
-    # How often to validate a connection (in seconds)
+    # How often to validate a connection (in seconds).
+    # Validation is done only when a connection is borrowed from the pool and not done actively while lays in the pool.
     config :jdbc_validation_timeout, :validate => :number, :default => 3600
   end