track replication destination health, and perform exponential back-off when sending transactions. does *not* yet retry transactions, but drops them on the floor if waiting for a server to recover.

1 files changed, 6 insertions, 0 deletions

diff --git a/synapse/storage/schema/transactions.sql b/synapse/storage/schema/transactions.sql
index 88e3e4e04d..de461bfa15 100644
--- a/synapse/storage/schema/transactions.sql
+++ b/synapse/storage/schema/transactions.sql
@@ -59,3 +59,9 @@ CREATE INDEX IF NOT EXISTS transaction_id_to_pdu_tx ON transaction_id_to_pdu(tra
 CREATE INDEX IF NOT EXISTS transaction_id_to_pdu_dest ON transaction_id_to_pdu(destination);
 CREATE INDEX IF NOT EXISTS transaction_id_to_pdu_index ON transaction_id_to_pdu(transaction_id, destination);
 
+-- To track destination health
+CREATE TABLE IF NOT EXISTS destinations(
+    destination TEXT PRIMARY KEY,
+    retry_last_ts INTEGER,
+    retry_interval INTEGER
+);