Adds new configuration option to specify reconnecting using the original configuration options when refreshing nodes (#290)

Author: supercaracal

README.md

@@ -28,6 +28,7 @@ gem 'redis-cluster-client'
 | `:fixed_hostname` | String | `nil` | required if client should connect to single endpoint with SSL |
 | `:slow_command_timeout` | Integer | `-1` | timeout used for "slow" queries that fetch metdata e.g. CLUSTER NODES, COMMAND |
 | `:concurrency` | Hash | `{ model: :on_demand, size: 5}` | concurrency settings, `:on_demand`, `:pooled` and `:none` are valid models, size is a max number of workers, `:none` model is no concurrency, Please choose the one suited your environment if needed. |
+| `:connect_with_original_config` | Boolean | `false` | `true` if client should retry the connection using the original endpoint that was passed in |
 
 Also, [the other generic options](https://github.com/redis-rb/redis-client#configuration) can be passed.
 But `:url`, `:host`, `:port` and `:path` are ignored because they conflict with the `:nodes` option.
@@ -106,6 +107,11 @@ RedisClient.cluster(concurrency: { model: :none }).new_client
 # Please choose the one suited your workloads.
 ```
 
+```ruby
+# To reconnect using the original configuration options on error. This can be useful when using a DNS endpoint and the underlying host IPs are all updated
+RedisClient.cluster(connect_with_original_config: true).new_client
+```
+
 ## Interfaces
 The following methods are able to be used like `redis-client`.
 * `#call`

lib/redis_client/cluster/router.rb

@@ -18,6 +18,8 @@ class Router
 
       def initialize(config, concurrent_worker, pool: nil, **kwargs)
         @config = config.dup
+        @original_config = config.dup if config.connect_with_original_config
+        @connect_with_original_config = config.connect_with_original_config
         @concurrent_worker = concurrent_worker
         @pool = pool
         @client_kwargs = kwargs
@@ -329,6 +331,7 @@ def update_cluster_info!
             # ignore
           end
 
+          @config = @original_config.dup if @connect_with_original_config
           @node = fetch_cluster_info(@config, @concurrent_worker, pool: @pool, **@client_kwargs)
         end
       end

lib/redis_client/cluster_config.rb

@@ -23,14 +23,15 @@ class ClusterConfig
 
     InvalidClientConfigError = Class.new(::RedisClient::Error)
 
-    attr_reader :command_builder, :client_config, :replica_affinity, :slow_command_timeout
+    attr_reader :command_builder, :client_config, :replica_affinity, :slow_command_timeout, :connect_with_original_config
 
-    def initialize(
+    def initialize( # rubocop:disable Metrics/AbcSize
       nodes: DEFAULT_NODES,
       replica: false,
       replica_affinity: :random,
       fixed_hostname: '',
       concurrency: nil,
+      connect_with_original_config: false,
       client_implementation: ::RedisClient::Cluster, # for redis gem
       slow_command_timeout: SLOW_COMMAND_TIMEOUT,
       **client_config
@@ -44,6 +45,7 @@ def initialize(
       @command_builder = client_config.fetch(:command_builder, ::RedisClient::CommandBuilder)
       @client_config = merge_generic_config(client_config, @node_configs)
       @concurrency = merge_concurrency_option(concurrency)
+      @connect_with_original_config = connect_with_original_config
       @client_implementation = client_implementation
       @slow_command_timeout = slow_command_timeout
       @mutex = Mutex.new
@@ -56,6 +58,7 @@ def dup
         replica_affinity: @replica_affinity,
         fixed_hostname: @fixed_hostname,
         concurrency: @concurrency,
+        connect_with_original_config: @connect_with_original_config,
         client_implementation: @client_implementation,
         slow_command_timeout: @slow_command_timeout,
         **@client_config