Files
scylladb/service/storage_proxy_stats.hh
Konstantin Osipov 56f3bda4c7 metrics: introduce a metric for non-local reads
A read which arrived to a non-replica and had to be forwarded to a
replica by the coordinator is accounted in an own metric,
reads_coordinator_outside_replica_set.
Most often such read is produced by a driver which is unaware of
token distribution on the ring.

If a read was forwarded to another replica due to heat weighted
load balancing or query preference set by the user, it's not accounted
in the metric.

In case of a multi-partition read (a query using IN statement,
e.g. x in (1, 2, 3)), if any of the keys is read from a
non-local node the read is accounted as a non-local.
The rationale behind it is that if the user tries to be careful and send
IN queries only to the same vnode, they are rewarded with the counter
staying at zero, while if they send multi-partition IN queries without
any precautions, they will see the metric go up which gives them a
starting point for investigating performance problems.

Closes #4338
2019-07-08 19:23:38 +03:00

180 lines
6.0 KiB
C++

/*
* Copyright (C) 2018 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "gms/inet_address.hh"
#include "utils/estimated_histogram.hh"
#include "utils/histogram.hh"
#include <seastar/core/metrics.hh>
namespace service {
namespace storage_proxy_stats {
// split statistics counters
struct split_stats {
static seastar::metrics::label datacenter_label;
static seastar::metrics::label op_type_label;
private:
struct stats_counter {
uint64_t val = 0;
};
// counter of operations performed on a local Node
stats_counter _local;
// counters of operations performed on external Nodes aggregated per Nodes' DCs
std::unordered_map<sstring, stats_counter> _dc_stats;
// collectd registrations container
seastar::metrics::metric_groups _metrics;
// a prefix string that will be used for a collectd counters' description
sstring _short_description_prefix;
sstring _long_description_prefix;
// a statistics category, e.g. "client" or "replica"
sstring _category;
// type of operation (data/digest/mutation_data)
sstring _op_type;
// whether to register per-endpoint metrics automatically
bool _auto_register_metrics;
public:
/**
* @param category a statistics category, e.g. "client" or "replica"
* @param short_description_prefix a short description prefix
* @param long_description_prefix a long description prefix
*/
split_stats(const sstring& category, const sstring& short_description_prefix, const sstring& long_description_prefix, const sstring& op_type, bool auto_register_metrics = true);
void register_metrics_local();
void register_metrics_for(gms::inet_address ep);
/**
* Get a reference to the statistics counter corresponding to the given
* destination.
*
* @param ep address of a destination
*
* @return a reference to the requested counter
*/
uint64_t& get_ep_stat(gms::inet_address ep);
};
struct write_stats {
// total write attempts
split_stats writes_attempts;
split_stats writes_errors;
split_stats background_replica_writes_failed;
// write attempts due to Read Repair logic
split_stats read_repair_write_attempts;
utils::timed_rate_moving_average write_unavailables;
utils::timed_rate_moving_average write_timeouts;
utils::timed_rate_moving_average_and_histogram write;
utils::estimated_histogram estimated_write;
uint64_t writes = 0;
// A CQL write query arrived to a non-replica node and was
// forwarded by a coordinator to a replica
uint64_t writes_coordinator_outside_replica_set = 0;
// A CQL read query arrived to a non-replica node and was
// forwarded by a coordinator to a replica
uint64_t reads_coordinator_outside_replica_set = 0;
uint64_t background_writes = 0; // client no longer waits for the write
uint64_t background_write_bytes = 0;
uint64_t queued_write_bytes = 0;
uint64_t throttled_writes = 0; // total number of writes ever delayed due to throttling
uint64_t throttled_base_writes = 0; // current number of base writes delayed due to view update backlog
uint64_t background_writes_failed = 0;
std::chrono::microseconds last_mv_flow_control_delay; // delay added for MV flow control in the last request
public:
write_stats();
write_stats(const sstring& category, bool auto_register_stats);
void register_metrics_local();
void register_metrics_for(gms::inet_address ep);
};
struct stats : public write_stats {
utils::timed_rate_moving_average read_timeouts;
utils::timed_rate_moving_average read_unavailables;
utils::timed_rate_moving_average range_slice_timeouts;
utils::timed_rate_moving_average range_slice_unavailables;
uint64_t read_repair_attempts = 0;
uint64_t read_repair_repaired_blocking = 0;
uint64_t read_repair_repaired_background = 0;
uint64_t global_read_repairs_canceled_due_to_concurrent_write = 0;
// number of mutations received as a coordinator
uint64_t received_mutations = 0;
// number of counter updates received as a leader
uint64_t received_counter_updates = 0;
// number of forwarded mutations
uint64_t forwarded_mutations = 0;
uint64_t forwarding_errors = 0;
// number of read requests received as a replica
uint64_t replica_data_reads = 0;
uint64_t replica_digest_reads = 0;
uint64_t replica_mutation_data_reads = 0;
uint64_t replica_cross_shard_ops = 0;
utils::timed_rate_moving_average_and_histogram read;
utils::timed_rate_moving_average_and_histogram range;
utils::estimated_histogram estimated_read;
utils::estimated_histogram estimated_range;
uint64_t reads = 0;
uint64_t foreground_reads = 0; // client still waits for the read
uint64_t read_retries = 0; // read is retried with new limit
uint64_t speculative_digest_reads = 0;
uint64_t speculative_data_reads = 0;
// Data read attempts
split_stats data_read_attempts;
split_stats data_read_completed;
split_stats data_read_errors;
// Digest read attempts
split_stats digest_read_attempts;
split_stats digest_read_completed;
split_stats digest_read_errors;
// Mutation data read attempts
split_stats mutation_data_read_attempts;
split_stats mutation_data_read_completed;
split_stats mutation_data_read_errors;
public:
stats();
void register_metrics_local();
void register_metrics_for(gms::inet_address ep);
};
}
}