implement background task queue

.config/cypress-devcontainer.yml

@@ -223,17 +223,42 @@ id: 'aidx'
 # Number of worker processes
 #clusterLimit: 1
 
+# +-------------------------+
+# | Job concurrency options |
+# +-------------------------+
+#
+### Available options:
+# [type]JobConcurrency - limits the number jobs that can run at the same time.
+#   Sharkey will allow this many jobs of this type *per worker process*.
+# [type]JobPerSec - limits the total number of jobs that may complete within a single second.
+#   If this limit is exceeded, then Sharkey will pause this type of job until the next second.
+# [type]JobMaxAttempts - limits the number of times that a job is allowed to fail and re-try before it's permanently stopped.
+#   If this limit is exceeded, then the job is considered "failed" and recorded for debugging.
+#
+### Job types:
+# inbox - processes ActivityPub messages (AKA "Activities") received from remote instances.
+#   All inbound activities are queued and processed in chronological order by this job.
+# deliver - processes ActivityPub messages (AKA "Activities") being set to remote instances.
+#   All outbound activities are queued and processed in chronological order by this job.
+# relationship - processes user-to-user tasks including follow/unfollow, block/unblock, account migrations, and all follow import jobs.
+# background - processes background synchronization tasks that need to happen soon (but not immediately), such as remote user updates and instance metadata updates.
+
 # Job concurrency per worker
-# deliverJobConcurrency: 128
-# inboxJobConcurrency: 16
+#deliverJobConcurrency: 128
+#inboxJobConcurrency: 16
+#relationshipJobConcurrency: 16
+#backgroundJobConcurrency: 32
 
 # Job rate limiter
-# deliverJobPerSec: 128
-# inboxJobPerSec: 32
+#deliverJobPerSec: 128
+#inboxJobPerSec: 32
+#relationshipJobPerSec: 64
+#backgroundJobPerSec: 256
 
 # Job attempts
-# deliverJobMaxAttempts: 12
-# inboxJobMaxAttempts: 8
+#deliverJobMaxAttempts: 12
+#inboxJobMaxAttempts: 8
+#backgroundJobMaxAttempts: 8
 
 # IP address family used for outgoing request (ipv4, ipv6 or dual)
 #outgoingAddressFamily: ipv4