launch background worker threads

src/Hash2Pub/PostService.hs

@@ -121,8 +121,8 @@ instance DHT d => Service PostService d where
                 -- web server
                 (Warp.runSettings warpSettings $ postServiceApplication thisService)
                 $ concurrently
-                    -- post queue processing
-                    (processIncomingPosts thisService)
+                    -- background processing workers
+                    (launchWorkerThreads thisService)
                     -- statistics/ measurements
                     (launchStatsThreads thisService)
         -- update thread ID after fork
@@ -604,6 +604,12 @@ instance {-# OVERLAPPABLE #-} Read a => MimeUnrender PlainText a where
 -- TODO: make configurable
 numParallelDeliveries = 10
 
+launchWorkerThreads :: DHT d => PostService d -> IO ()
+launchWorkerThreads serv = concurrently_
+    (processIncomingPosts serv)
+    $ concurrently_
+        (fetchTagPosts serv)
+        (relayWorker serv)
 
 -- | process the pending relay inbox of incoming posts from the internal queue:
 -- Look up responsible relay node for given hashtag and forward post to it