Files
scylla/locator/ec2_snitch.hh
Takuya ASADA 0b894a7cac locator::ec2_snitch: change retry logic to exponential backoff
Since Amazon recommended to use exponential backoff logic when retries
to call AWS API, we should switch the logic on ec2_snitch.

see https://docs.aws.amazon.com/general/latest/gr/api-retries.html

Related with #12160

Closes scylladb/scylladb#13442
2023-12-25 18:17:23 +02:00

42 lines
1.5 KiB
C++

/*
* SPDX-License-Identifier: Apache-2.0
*
* Modified by ScyllaDB
* Copyright (C) 2015-present ScyllaDB
*/
#pragma once
#include "locator/production_snitch_base.hh"
#include <seastar/http/response_parser.hh>
#include <seastar/net/api.hh>
#include "utils/exponential_backoff_retry.hh"
namespace locator {
class ec2_snitch : public production_snitch_base {
public:
static constexpr const char* TOKEN_REQ_ENDPOINT = "/latest/api/token";
static constexpr const char* ZONE_NAME_QUERY_REQ = "/latest/meta-data/placement/availability-zone";
static constexpr const char* AWS_QUERY_SERVER_ADDR = "169.254.169.254";
static constexpr uint16_t AWS_QUERY_SERVER_PORT = 80;
static constexpr int AWS_API_CALL_RETRIES = 10;
ec2_snitch(const snitch_config&);
virtual future<> start() override;
virtual sstring get_name() const override {
return "org.apache.cassandra.locator.Ec2Snitch";
}
protected:
future<> load_config(bool prefer_local);
future<sstring> aws_api_call(sstring addr, uint16_t port, const sstring cmd, std::optional<sstring> token);
future<sstring> read_property_file();
private:
connected_socket _sd;
input_stream<char> _in;
output_stream<char> _out;
http_response_parser _parser;
sstring _req;
exponential_backoff_retry _ec2_api_retry = exponential_backoff_retry(std::chrono::seconds(5), std::chrono::seconds(2560));
future<sstring> aws_api_call_once(sstring addr, uint16_t port, const sstring cmd, std::optional<sstring> token);
};
} // namespace locator