Jaeger是收集全链路跟踪的信息，在Jaeger收集的信息中，有请求的url信息，有每个请求的时间间隔，借助这些信息可以进行报警，比如一次较长的请求，或者是某些请求的次数和先后等。不管报警的业务规则是什么，首先得收集Jaeger中的信息。

Jaeger有api可以提供这些信息，比如

/api/services，获取所有服务

/api/traces?service={servicename}获取该服务下的所有跟踪

/api/traces/{traceid}获取某个跟踪的信息等

/api/traces?end={endtime}&limit={20}&lookback={1h}&service={servicename}&start={starttime}按条件查询跟踪信息等api

下面代码定义Jaeger中的实体类，类中的属性可以根据自己的型业务规则收集，这里定义不完整

using System.Collections.Generic;namespace JaegerAlert{    /// 
    /// 服务报警    /// 
    public class AlertList    {        public string ServiceName { get; set; }        public List
    
      Alerts { get; set; }    }    /// 
     
    /// 报警条目    /// 
    public class AlertItem    {        public string TraceID { get; set; }        public long StartTime { get; set; }        public long Duration { get; set; }        public string Method { get; set; }        public string Operation { get; set; }    }    /// 
     
    /// 服务数据    /// 
    public class ServicesData    {        public string[] Data { get; set; }        public int Total { get; set; }        public int Limit { get; set; }        public int Offset { get; set; }    }    /// 
     
    /// 跟踪数据    /// 
    public class TracesData    {        public TracesItem[] Data { get; set; }        public int Total { get; set; }        public int Limit { get; set; }        public int Offset { get; set; }    }    /// 
     
    /// 跟踪条目    /// 
    public class TracesItem    {        public string TraceID { get; set; }        public Span[] Spans { get; set; }    }    /// 
     
    /// Span    /// 
    public class Span    {        public string TraceID { get; set; }        public string SpanID { get; set; }        public bool IsAlertMark => TraceID == SpanID;        public int Flags { get; set; }        public string OperationName { get; set; }        public long StartTime { get; set; }        public long Duration { get; set; }        public Tag[] Tags { get; set; }    }    /// 
     
    /// Tag    /// 
    public class Tag    {        public string Key { get; set; }        public string Type { get; set; }        public string Value { get; set; }    }}
    

这里简单进行了收集，转换成了自己的数据集合，方便对接自己的报警平台：

using Microsoft.AspNetCore.Mvc;using Microsoft.Extensions.Logging;using System.Collections.Generic;using System.Linq;using System.Net.Http;using System.Threading.Tasks;namespace JaegerAlert.Controllers{    [ApiController]    [Route("[controller]")]    public class HomeController : ControllerBase    {        private readonly IHttpClientFactory _clientFactory;        private readonly ILogger
    
      _logger;        public HomeController(ILogger
     
       logger, IHttpClientFactory clientFactory)        {            _clientFactory = clientFactory;            _logger = logger;        }        [HttpGet]        public async Task
      
       
        > Get()        {            _logger.LogInformation("获取警报列表");            return await GetServices();        }        /// 
        
        /// 获取所有服务        /// 
        /// 
                async Task
        
         
          > GetServices() { var service = await GetJaegerServices(); var services = new List
          
           (); foreach (var serviceName in service.Data) { if (serviceName == "jaeger-query") { continue; } var alerts = new List
           
            (); var tracesModels = await GetJaegerTraces(serviceName); foreach (var traces in tracesModels.Data) { foreach (var span in traces.Spans) { if (span.IsAlertMark) { var method = span.Tags.SingleOrDefault(s => s.Key == "http.method")?.Value; var operation = span.Tags.SingleOrDefault(s => s.Key == "http.url")?.Value; alerts.Add(new AlertItem { TraceID = traces.TraceID, Duration = span.Duration, Method = method, Operation = operation, StartTime = span.StartTime }); } } } services.Add(new AlertList() { ServiceName = serviceName, Alerts = alerts }); } return services; } /// 
            
 /// 获取服务下的跟踪条目 /// 
 /// 
             /// 
             async Task
            
              GetJaegerTraces(string serviceName) { using var client = _clientFactory.CreateClient("Jaeger"); var request = new HttpRequestMessage(HttpMethod.Get, $"/api/traces?service={serviceName}"); using var response = await client.SendAsync(request); if (response.IsSuccessStatusCode) { var jsonString = await response.Content.ReadAsStringAsync(); var traces = Newtonsoft.Json.JsonConvert.DeserializeObject
             
              (jsonString); return traces; } else { return new TracesData(); } } /// 
              
 /// 获取服务 /// 
 /// 
               async Task
              
                GetJaegerServices() { using var client = _clientFactory.CreateClient("Jaeger"); var request = new HttpRequestMessage(HttpMethod.Get, "/api/services"); using var response = await client.SendAsync(request); if (response.IsSuccessStatusCode) { var jsonString = await response.Content.ReadAsStringAsync(); var service = Newtonsoft.Json.JsonConvert.DeserializeObject
               
                (jsonString); return service; } else { return new ServicesData(); } } } }
               
              
             
            
           
          
         
        
       
      
     
    

请求结果：

收集到数据后，就可以应用到报警平台上，如果报警平台有api，可以进行调用处理；还可以把这些数据推送到时序数据库中，如InfluxDB，再通过Grafana展示出来，进行实时展时跟踪，关于跟踪的细节和业务规则有关系，如果以后工作中遇到这类处理，到时再追加一篇博文进行细说。