前言
在咱们日常运维/运维开发工作中各种零碎次要分为两大流派
- 本文次要探讨下有agent侧一些注意事项
客户端服务端的C/S架构
长处
- c/s架构相比于基于ssh的并发和吞吐量要高的多
- 利用agent可做的事件很多以及更精准的管制
毛病
- 性能更新须要降级agent
- agent如果保活是个头疼的问题
- 机器上agent过多如何治理又是个问题
agentless架构
特点无侵入性agent:典型利用就是基于ssh ansible
长处
- 无agent不须要关怀保活和笼罩问题
- 性能更新次要在server端实现
毛病
- 基于ssh的性能/性能较差
经典client案例
配置管理/批量操作
- Saltstack Minion
- Puppet Agent
监控
- prometheus 各种各样的exporter: node_exporter
- open-falcon falcon-agent
- Zabbix Agent
C/S架构中agent侧注意事项
agent资源耗费
代码该当简洁，防止过多资源耗费agent资源监控能够应用prometheus的 client_golang ，默认会export 过程的cpu_user 、fd、mem等信息帮忙咱们定位资源耗费
# HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.# TYPE process_cpu_seconds_total counterprocess_cpu_seconds_total 38913.32# HELP process_max_fds Maximum number of open file descriptors.# TYPE process_max_fds gaugeprocess_max_fds 6.815744e+06# HELP process_open_fds Number of open file descriptors.# TYPE process_open_fds gaugeprocess_open_fds 15# HELP process_resident_memory_bytes Resident memory size in bytes.# TYPE process_resident_memory_bytes gaugeprocess_resident_memory_bytes 1.4659584e+07# HELP process_start_time_seconds Start time of the process since unix epoch in seconds.# TYPE process_start_time_seconds gaugeprocess_start_time_seconds 1.59350253732e+09# HELP process_virtual_memory_bytes Virtual memory size in bytes.# TYPE process_virtual_memory_bytes gaugeprocess_virtual_memory_bytes 1.201352704e+09# HELP process_virtual_memory_max_bytes Maximum amount of virtual memory available in bytes.# TYPE process_virtual_memory_max_bytes gaugeprocess_virtual_memory_max_bytes -1agent如何降级治理
举例:当初要降级agent版本 from v1.0 to v1.1
思路一:应用管理工具治理
如ansible-playbook 能够参考我之前的文章 应用ansible-playbook实现dnsdist疾速劫持工具
咱们能够应用上面python代码将跑playbook封装成一个办法，应用的时候只须要传入 ip列表，yaml，和额定的变量dict即可
咳咳:这个计划典型问题就是受限于单个ansible性能问题(很多小伙伴都被折磨过吧)，当然能够将大量的ip列表分片分发给多个ansible-server执行，再将后果merge一下
t = PlaybookApi([ip], yaml_path, {"conf_dir": conf_dir, "bk_file_name": bk_file_name}) t.run()from collections import namedtuplefrom ansible.parsing.dataloader import DataLoaderfrom ansible.vars import VariableManagerfrom ansible.inventory import Inventoryfrom ansible.utils.vars import load_extra_varsfrom ansible.utils.vars import load_options_varsfrom ansible.executor.playbook_executor import PlaybookExecutorfrom ansible.plugins.callback import CallbackBaseclass ResultsCollector(CallbackBase): def __init__(self, *args, **kwargs): super(ResultsCollector, self).__init__(*args, **kwargs) self.host_ok = {} self.host_unreachable = {} self.host_failed = {} def v2_runner_on_unreachable(self, result): self.host_unreachable[result._host.get_name()] = result def v2_runner_on_ok(self, result, *args, **kwargs): self.host_ok[result._host.get_name()] = result def v2_runner_on_failed(self, result, *args, **kwargs): self.host_failed[result._host.get_name()] = result# class PlaybookApi(PlaybookExecutor):class PlaybookApi(PlaybookExecutor): def __init__(self, host_list, yaml_path, extra_vars): self.host_list = host_list self.yaml_path = yaml_path # self.kcache_path = kcache_path self.callback = ResultsCollector() self.extra_vars = extra_vars self.IpmiPlay() super(PlaybookApi, self).__init__(playbooks=[self.yaml_path], inventory=self.inventory, variable_manager=self.variable_manager, loader=self.loader, options=self.options, passwords={}) self._tqm._stdout_callback = self.callback def IpmiPlay(self): Options = namedtuple('Options', ['listtags', 'listtasks', 'listhosts', 'syntax', 'connection', 'module_path', 'forks', 'remote_user', 'private_key_file', 'ssh_common_args', 'ssh_extra_args', 'sftp_extra_args', 'scp_extra_args', 'become', 'become_method', 'become_user', 'verbosity', 'check', 'extra_vars']) self.options = Options(listtags=False, listtasks=False, listhosts=False, syntax=False, connection='ssh', module_path=None, forks=10, remote_user='', private_key_file=None, ssh_common_args='', ssh_extra_args='', sftp_extra_args='', scp_extra_args='', become=True, become_method='sudo', become_user='root', verbosity=3, check=False, extra_vars={}) self.loader = DataLoader() # create the variable manager, which will be shared throughout # the code, ensuring a consistent view of global variables variable_manager = VariableManager() variable_manager.extra_vars = load_extra_vars(loader=self.loader, options=self.options) variable_manager.options_vars = load_options_vars(self.options) self.variable_manager = variable_manager # create the inventory, and filter it based on the subset specified (if any) self.inventory = Inventory(loader=self.loader, variable_manager=self.variable_manager, host_list=self.host_list) self.variable_manager.set_inventory(self.inventory) self.variable_manager.extra_vars = self.extra_vars def get_result(self): # print("calling in get_result") self.results_raw = {'success': {}, 'failed': {}, "unreachable": {}} for host, result in self.callback.host_ok.items(): self.results_raw['success'][host] = result for host, result in self.callback.host_failed.items(): self.results_raw['failed'][host] = result for host, result in self.callback.host_unreachable.items(): self.results_raw['unreachable'][host] = result._result['msg'] return self.results_rawif __name__ == '__main__': h = ["127.0.0.1"] yaml = "systemd_stop.yaml" api = PlaybookApi(h, yaml, {"app": "falcon-judge"}) api.run() res = api.get_result() for k, v in res.items(): for kk, vv in v.items(): print(kk, vv._result)思路二: 代码中实现自降级
以falcon-agent代码为例，代码地址 https://github.com/ning1875/falcon-plus/tree/master/modules/agent 整体实现流程:
ps:原谅我那蜘蛛爬的字吧
实现剖析
- 机器上个别会选用一种daemontools作为服务托管工具:如 supervisor和systemd，而systemd更广泛些
- 在机器上跑的服务最小可由三个文件组成: 一个二进制可执行文件、一个配置文件、一个service文件
- 所以服务的自降级就是这三个文件的降级
文件降级完后如何重启服务呢:以systemd为例只须要发送term信号给本身过程即可，即kill 过程pid
pid := os.Getpid()thisPro, _ := os.FindProcess(pid)thisPro.Signal(os.Kill)agent如何治理版本: 在const中指定
// changelog:// 3.1.3: code refactor// 3.1.4: bugfix ignore configuration// 5.0.0: 反对通过配置管制是否开启/run接口；收集udp流量数据；du某个目录的大小// 5.1.0: 同步插件的时候不再应用checksum机制// 5.1.1: 修复往多个transfer发送数据的时候crash的问题// 5.1.2: ignore mount point when blocks=0// 6.0.0: agent自降级,新增一些监控项// 6.0.1: agent collect level// 6.0.2: 增加单核监控开关默认不关上,单核监控tag变更为core=core0x ,增加mem.available.percent// 6.0.3: 减少sys.uptime// 6.0.4: 修复cpu.iowait>100的bug// 6.0.5: 增加过程采集监控，距离30s// 6.0.6: 调整内置的采集func距离 disk io相干和tcp 10s-->30s,agent_version 整数代表以后版本,去掉动静监控办法// 6.0.7: ntp 反对chronyc ，服务监控rpc call 距离调整为一分钟// 6.0.8: 批改监控项抓取工夫距离， 10s只保留cpu，解决断点问题// 6.0.9: 修复dfa dfb块设施采集,修复不同版本ss-s的bug// 6.1.0: 修复机器上主机名被改case,使ip转化为nxx-xx-xx的模式const ( VERSION = "6.1.0" COLLECT_INTERVAL = time.Second URL_CHECK_HEALTH = "url.check.health" NET_PORT_LISTEN = "net.port.listen" DU_BS = "du.bs" PROC_NUM = "proc.num" UPTIME = "sys.uptime")- 服务端如何开启降级开关:在hbs http接口开启
- 客户端如何check要不要降级:只需check版本是否统一和是否在降级过程中
- 服务端如何做到并发管制: 只需查看redis降级队列在降级的数量和预设的阈值比照
管理员如何发动降级:只须要给hbs发动http申请关上降级开关
curl -X POST http://127.0.0.1:6031/agent/upgrade -d '{"wgeturl":"http://${your_cdn_addr}/file/open-falcon","version":"6.0.1","binfile_md5":"35ac8534c0b31237e844ef8ee2bb9b9e"}'- 管理员
- 如何进步降级并发:其实就是如何让下载并发更高，即采纳大带宽nginx或cdn或者给不同批次agent发送不同下载cdn地址
毛病
- 整体实现还比拟毛糙没有笼罩灰度和回滚(只能再发上一个版本)
- 过程中没有直观的降级进度展现(只能通过hbs接口获取agent版本做求和)
过程阐明:
http-req --->hbs --->开启降级开关--->查看agent心跳信息中版本号，并查看以后hbs降级队列--->发送降级指令给agent ---> agent通过 降级命令中的url地址和指标版本号下载新的二进制（会有备份和回滚逻辑）--->agent check没有问题后获取本身的pid向本人发送kill信号 --->agent退出而后会被systemd拉起打到降级的目标--->新的心跳信息中版本checkok不会持续降级降级举例说明:
1. falcon-agent新加了采集指标，测试OK后在代码中打上新的版本号比方6.0.0（现有是6.0.1）2. 而后将新版 放到下载服务器的门路下 wget http://${your_cdn_addr}/file/open-falcon/bin_6.0.13. 而后向hbs 发送降级的http申请（这里有个爱护机制:只能在hbs本机发动）4. 而后通过hbs 的http接口查问以后心跳上来的agent的版本查看降级进度 ，curl -s http://localhost:6031/agentversions |python -m "json.tool"5. 同时须要连贯的redis集群察看 agent_upgrade_set 这个set的值，redis-cli -h ip -p port -c smembers agent_upgrade_set & scard agent_upgrade_set6. 目前看并发2000能够把一台下载的nginx万兆网卡流量打满。1.24GB/s## falcon-agent 自降级命令curl -X POST http://127.0.0.1:6031/agent/upgrade -d '{"wgeturl":"http://${your_cdn_addr}/file/open-falcon","version":"6.0.1","binfile_md5":"35ac8534c0b31237e844ef8ee2bb9b9e"}'curl -X GET http://127.0.0.1:6031/agent/upgrade/nowargs{"msg":"success","data":{"type":0,"wgeturl":"http://${your_cdn_addr}/file/open-falcon","version":"6.0.1","binfile_md5":"35ac8534c0b31237e844ef8ee2bb9b9e","cfgfile_md5":""}}curl http://127.0.0.1:6031/agentversions{"msg":"success","data":{"n3-021-225":"6.0.1"}}curl -X DELETE http://127.0.0.1:6031/agent/upgrade{"msg":"success","data":"勾销降级胜利"} uri: url: http://127.0.0.1:6031/agent/upgrade method: POST body: {"wgeturl":"http://${your_cdn_addr}/file/open-falcon","version":"6.0.2","binfile_md5":"f5c597f15e379a77d1e2ceeec7bd99a8"} status_code: 200 body_format: json