When a counter write times out (due to rpc::timeout_error or timed_out_error),
the code was throwing mutation_write_timeout_exception but not marking the
write_timeouts metric. This resulted in counter write timeouts not being
counted in the scylla_storage_proxy_coordinator_write_timeouts metric.
Regular writes go through mutate_internal -> mutate_end, which catches
mutation_write_timeout_exception and marks the metric. However, counter
writes use a separate code path (mutate_counters) that has its own
exception handling but was missing the metric update.
This fix adds get_stats().write_timeouts.mark() before throwing the
timeout exception in the counter write path, consistent with how the
CAS path handles cas_write_timeouts.
Refs: https://scylladb.atlassian.net/browse/SCYLLADB-245
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#28019