Changes cache hosts warning / critical levels and continue on multiple hosts

app/code/Magento/CacheInvalidate/Model/PurgeCache.php

@@ -118,6 +118,7 @@ private function splitTags($tagsPattern)
     private function sendPurgeRequestToServers($socketAdapter, $servers, $formattedTagsChunk)
     {
         $headers = [self::HEADER_X_MAGENTO_TAGS_PATTERN => $formattedTagsChunk];
+        $unresponsiveServerCount = 0;
         foreach ($servers as $server) {
             $headers['Host'] = $server->getHost();
             try {
@@ -131,10 +132,19 @@ private function sendPurgeRequestToServers($socketAdapter, $servers, $formattedT
                 $socketAdapter->read();
                 $socketAdapter->close();
             } catch (\Exception $e) {
-                $this->logger->critical($e->getMessage(), compact('server', 'formattedTagsChunk'));
-                return false;
+                $unresponsiveServerCount++;
+                if ($unresponsiveServerCount == count($servers)) {
+                    $this->logger->critical('Available cache server(s) are unresponsive: ' . $e->getMessage(), compact('server',
+                        'formattedTagsChunk'));
+                    return false;
+                } else {
+                    $this->logger->warning('Unresponsive cache server hit, yet more cache servers are available: ' .
+                        $e->getMessage(), compact('server', 'formattedTagsChunk'));
+                    continue;
+                }
             }
         }
+
         $this->logger->execute(compact('servers', 'formattedTagsChunk'));
         return true;
     }

lib/internal/Magento/Framework/Cache/InvalidateLogger.php

@@ -65,4 +65,17 @@ public function critical($message, $params)
     {
         $this->logger->critical($message, $this->makeParams($params));
     }
+
+    /**
+     * Log warning
+     *
+     * @param string $message
+     * @param mixed $params
+     * @return void
+     */
+    public function warning($message, $params)
+    {
+        $this->logger->warning($message, $this->makeParams($params));
+    }
+
 }