Gitlab 自动缩放：“无法请求作业：运行程序请求并发满足”

Question

我们已经按照官方文档中的描述设置了一个 Gitlab 自动缩放主机。

gitlab-runner 实例可以工作，被 gitlab.org 识别，并且还成功生成运行器来执行作业。

然而，这些工作并没有在生成的跑步者身上真正开始。他们坚持在这一点上。

我们打开了调试级别日志记录，唯一看起来不愉快的消息是这些重复的消息：

msg="Failed to request job: runner requestConcurrency meet" 

config.toml 看起来像这样：

concurrent = 20
check_interval = 10
log_level = "debug"
log_format = "text"

[session_server]
  session_timeout = 1800

[[runners]]
  name = "gitlab-runner-master"
  url = "https://gitlab.com/"
  token = "blabla"
  executor = "docker+machine"
  limit = 25
  [runners.custom_build_dir]
  [runners.cache]
    Type = "s3"
    Shared = true
    [runners.cache.s3]
       ServerAddress = "s3.amazonaws.com"
       AccessKey = "blabla"
       SecretKey = "blabla"
       BucketName = "gitlab.cache.dyynamo.net"
       BucketLocation = "us-east-1"
    [runners.cache.gcs]
    [runners.cache.azure]
  [runners.docker]
    tls_verify = false
    image = "amd64/ubuntu:16.04"
    privileged = true
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = true
    volumes = ["/cache"]
    shm_size = 0
  [runners.machine]
    IdleCount = 0
    IdleTime = 600
    MaxBuilds = 100
    MachineDriver = "amazonec2"
    MachineName = "gitlab-docker-machine-%s"

有什么想法可能是什么问题吗？

还注意到这个仍然悬而未决的类似问题。