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service/storage_proxy: add trace points for the actual read executor type

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There is currently a trace point for when the read executor is created,
but this only contains the initial replica set and doesn't mention which
read executor is created in the end. This patch adds trace points for
each different return path, so it is clear from the trace whether
speculative read can happen or not.
This commit is contained in:
Botond Dénes
2023-08-31 04:24:26 -04:00
parent 727e519c3a
commit ff29f43060
1 changed files with 6 additions and 0 deletions
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6
service/storage_proxy.cc
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@@ -5352,6 +5352,7 @@ result<::shared_ptr<abstract_read_executor>> storage_proxy::get_read_executor(lw
// Speculative retry is disabled *OR* there are simply no extra replicas to speculate.
if (retry_type == speculative_retry::type::NONE || block_for == all_replicas.size()
|| (repair_decision == db::read_repair_decision::DC_LOCAL && is_datacenter_local(cl) && block_for == target_replicas.size())) {
tracing::trace(trace_state, "Creating never_speculating_read_executor - speculative retry is disabled or there are no extra replicas to speculate with");
return ::make_shared<never_speculating_read_executor>(schema, cf, p, std::move(erm), cmd, std::move(pr), cl, std::move(target_replicas), std::move(trace_state), std::move(permit), rate_limit_info);
}
@@ -5359,6 +5360,7 @@ result<::shared_ptr<abstract_read_executor>> storage_proxy::get_read_executor(lw
// CL.ALL, RRD.GLOBAL or RRD.DC_LOCAL and a single-DC.
// We are going to contact every node anyway, so ask for 2 full data requests instead of 1, for redundancy
// (same amount of requests in total, but we turn 1 digest request into a full blown data request).
tracing::trace(trace_state, "always_speculating_read_executor (all targets)");
return ::make_shared<always_speculating_read_executor>(schema, cf, p, std::move(erm), cmd, std::move(pr), cl, block_for, std::move(target_replicas), std::move(trace_state), std::move(permit), rate_limit_info);
}
@@ -5367,16 +5369,20 @@ result<::shared_ptr<abstract_read_executor>> storage_proxy::get_read_executor(lw
auto local_dc_filter = erm->get_topology().get_local_dc_filter();
if (!extra_replica || (is_datacenter_local(cl) && !local_dc_filter(*extra_replica))) {
slogger.trace("read executor no extra target to speculate");
tracing::trace(trace_state, "Creating never_speculating_read_executor - there are no extra replicas to speculate with");
return ::make_shared<never_speculating_read_executor>(schema, cf, p, std::move(erm), cmd, std::move(pr), cl, std::move(target_replicas), std::move(trace_state), std::move(permit), rate_limit_info);
} else {
target_replicas.push_back(*extra_replica);
slogger.trace("creating read executor with extra target {}", *extra_replica);
tracing::trace(trace_state, "Added extra target {} for speculative read", *extra_replica);
}
}
if (retry_type == speculative_retry::type::ALWAYS) {
tracing::trace(trace_state, "Creating always_speculating_read_executor");
return ::make_shared<always_speculating_read_executor>(schema, cf, p, std::move(erm), cmd, std::move(pr), cl, block_for, std::move(target_replicas), std::move(trace_state), std::move(permit), rate_limit_info);
} else {// PERCENTILE or CUSTOM.
tracing::trace(trace_state, "Creating speculating_read_executor");
return ::make_shared<speculating_read_executor>(schema, cf, p, std::move(erm), cmd, std::move(pr), cl, block_for, std::move(target_replicas), std::move(trace_state), std::move(permit), rate_limit_info);
}
}