exchange

commit b9899d4cafa8e3a16f235ecad2816f7c397386a1
parent 8fa1244b92d3f779b67809713fa991f56d19ce78
Author: Christian Grothoff <christian@grothoff.org>
Date:   Thu,  6 Aug 2026 22:42:23 +0200

retry KYC rule evaluation on serialization failure

Diffstat:
M
src/exchange/taler-exchange-aggregator.c
 | 
57
++++++++++++++++++++++++++++++++++++++++++++++++++++++++-

1 file changed, 56 insertions(+), 1 deletion(-)
diff --git a/src/exchange/taler-exchange-aggregator.c b/src/exchange/taler-exchange-aggregator.c
@@ -807,6 +807,40 @@ trigger_wire_transfer (struct AggregationUnit *au)
 }
 
 
+/**
+ * A step of #evaluate_rules() failed.  If that was a serialization failure
+ * and we still have retries left, roll the transaction back and evaluate the
+ * rules again from the top; the KYC measure, the transient's requirement_row
+ * and the append-only deferral record are written in one transaction and
+ * nothing else ever rescans transients, so dropping them here loses them for
+ * good.
+ *
+ * @param[in,out] au aggregation we are working on
+ * @param qs status that made the caller stop
+ * @return true if a retry was scheduled and the caller must return at once
+ */
+static bool
+retry_rule_evaluation (struct AggregationUnit *au,
+                       enum GNUNET_DB_QueryStatus qs)
+{
+  if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
+    return false;
+  if (au->retries++ >= MAX_RETRIES)
+    return false;
+  TALER_EXCHANGEDB_rollback (pg);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Serialization failure evaluating KYC rules, trying again!\n");
+  au->ru = TALER_EXCHANGEDB_begin_rule_update (
+    pg,
+    &attribute_key,
+    &au->h_normalized_payto,
+    false, /* aggregation does not apply to wallets */
+    &evaluate_rules,
+    au);
+  return (NULL != au->ru);
+}
+
+
 static void
 evaluate_rules (
   struct AggregationUnit *au,
@@ -869,6 +903,9 @@ evaluate_rules (
   {
     TALER_KYCLOGIC_rules_free (lrs);
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    if (retry_rule_evaluation (au,
+                               qs))
+      return;
     cleanup_and_next (au);
     return;
   }
@@ -906,6 +943,10 @@ evaluate_rules (
                 "Failed to persist KYC requirement `%s' in DB!\n",
                 TALER_KYCLOGIC_rule2s (requirement));
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    TALER_KYCLOGIC_rules_free (lrs);
+    if (retry_rule_evaluation (au,
+                               qs))
+      return;
     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
       global_ret = EXIT_FAILURE;
     cleanup_and_next (au);
@@ -928,6 +969,9 @@ evaluate_rules (
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Failed to persist updated transient in in DB!\n");
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    if (retry_rule_evaluation (au,
+                               qs))
+      return;
     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
       global_ret = EXIT_FAILURE;
     cleanup_and_next (au);
@@ -951,6 +995,9 @@ evaluate_rules (
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Failed to persist deferral reason in DB!\n");
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    if (retry_rule_evaluation (au,
+                               qs))
+      return;
     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
       global_ret = EXIT_FAILURE;
     cleanup_and_next (au);
@@ -971,7 +1018,15 @@ evaluate_rules (
   }
 
   /* First commit, turns the rollback in cleanup into a NOP! */
-  commit_or_warn ();
+  qs = commit_or_warn ();
+  if (0 > qs)
+  {
+    if (retry_rule_evaluation (au,
+                               qs))
+      return;
+    if (GNUNET_DB_STATUS_HARD_ERROR == qs)
+      global_ret = EXIT_FAILURE;
+  }
   cleanup_and_next (au);
 }