更新服务#
SkyServe 支持更新已部署的服务，可用于更改：
副本代码（例如，
run/setup；对调试很有用）resources中的副本资源规范（例如，加速器或实例类型）service中的服务规范（例如，副本数量或自动伸缩规范）
更新期间，服务将保持可访问性且无停机，其端点也将保持不变。默认情况下应用滚动更新，您也可以指定蓝绿更新。
滚动更新#
要更新现有服务，请使用 sky serve update
$ sky serve update service-name new_service.yaml
SkyServe 将按照 new_service.yaml 中描述的新副本启动，具体行为如下：
更新开始，流量将继续重定向到现有的（旧）副本。
新副本（具有新设置）在后台启动。
无论何时，当新旧副本的总数超过预期的副本数量（基于自动伸缩器的决策）时，多余的旧副本将被缩减。
流量将同时重定向到新旧副本，直到所有新副本准备就绪。
提示
当只更新 service 字段，且服务任务中未指定 workdir 或 file_mounts 时，SkyServe 将通过应用新的服务规范并提升其版本来重用旧副本（有关版本信息，请参见 sky serve status）。这将显著减少更新服务所需的时间，并避免潜在的配额问题。
示例#
我们首先启动一个简单的 HTTP 服务
$ sky serve up examples/serve/http_server/task.yaml -n http-server
我们可以使用 sky serve status http-server 来检查服务状态
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 1 1m 41s READY 2/2 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 2 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 2 1 52.87.241.103 2 mins ago 1x AWS(vCPU=2) READY us-east-1
服务 http-server 的初始版本为 1。
假设我们想将服务的副本数量从 2 个更新为 3 个。我们可以通过更改 replicas 字段来更新任务 yaml 文件 examples/serve/http_server/task.yaml
# examples/serve/http_server/task.yaml
service:
readiness_probe:
path: /health
initial_delay_seconds: 20
replicas: 3
resources:
ports: 8081
cpus: 2+
workdir: examples/serve/http_server
run: python3 server.py
然后我们可以使用 sky serve update 来更新服务
$ sky serve update http-server examples/serve/http_server/task.yaml
SkyServe 将触发启动三个新的副本。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 2 6m 15s READY 2/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 6 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 2 1 52.87.241.103 6 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 3 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
http-server 4 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
http-server 5 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
每当新副本准备就绪，流量将同时重定向到新旧副本。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 1,2 10m 4s READY 3/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 10 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 2 1 52.87.241.103 10 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 3 2 3.93.241.163 1 min ago 1x AWS(vCPU=2) READY us-east-1
http-server 4 2 - 1 min ago 1x AWS(vCPU=2) PROVISIONING us-east-1
http-server 5 2 - 1 min ago 1x AWS(vCPU=2) PROVISIONING us-east-1
一旦新旧副本的总数超过请求的数量，旧副本将被缩减。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 1,2 10m 4s READY 3/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 10 mins ago 1x AWS(vCPU=2) SHUTTING_DOWN us-east-1
http-server 2 1 52.87.241.103 10 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 3 2 3.93.241.163 1 min ago 1x AWS(vCPU=2) READY us-east-1
http-server 4 2 18.206.226.82 1 min ago 1x AWS(vCPU=2) READY us-east-1
http-server 5 2 - 1 min ago 1x AWS(vCPU=2) PROVISIONING us-east-1
最终，我们将只剩下新副本准备好为用户请求提供服务。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 2 11m 42s READY 3/3 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 3 2 3.93.241.163 3 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 4 2 18.206.226.82 3 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 5 2 3.26.232.31 1 min ago 1x AWS(vCPU=2) READY us-east-1
蓝绿更新#
SkyServe 也支持蓝绿更新，使用以下命令：
$ sky serve update --mode blue_green service-name new_service.yaml
在此更新模式下，SkyServe 将按照 new_service.yaml 中描述的新副本启动，具体行为如下：
更新开始，流量将继续重定向到现有的（旧）副本。
新副本（具有新设置）在后台启动。
仅当所有新副本准备就绪后，流量才会重定向到新副本。
所有新副本准备就绪后，旧副本将被缩减。
更新期间，流量完全由旧版本或新版本的副本提供服务。sky serve status 显示最新的服务版本和每个副本的版本。
示例#
我们以同一个服务 http-server 为例。然后我们可以使用 sky serve update --mode blue_green 来更新服务
$ sky serve update http-server --mode blue_green examples/serve/http_server/task.yaml
SkyServe 将触发启动三个新的副本。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 2 6m 15s READY 2/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 6 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 2 1 52.87.241.103 6 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 3 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
http-server 4 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
http-server 5 2 - 21 secs ago 1x AWS(vCPU=2) PROVISIONING us-east-1
当新副本准备就绪时，流量仍将重定向到旧副本。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 1 10m 4s READY 3/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 10 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 2 1 52.87.241.103 10 mins ago 1x AWS(vCPU=2) READY us-east-1
http-server 3 2 3.93.241.163 1 min ago 1x AWS(vCPU=4) READY us-east-1
http-server 4 2 - 1 min ago 1x AWS(vCPU=4) PROVISIONING us-east-1
http-server 5 2 - 1 min ago 1x AWS(vCPU=4) PROVISIONING us-east-1
一旦新副本的总数满足要求，流量将重定向到新副本，旧副本将被缩减。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 2 10m 4s READY 3/5 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 1 1 54.173.203.169 10 mins ago 1x AWS(vCPU=2) SHUTTING_DOWN us-east-1
http-server 2 1 52.87.241.103 10 mins ago 1x AWS(vCPU=2) SHUTTING_DOWN us-east-1
http-server 3 2 3.93.241.163 1 min ago 1x AWS(vCPU=4) READY us-east-1
http-server 4 2 18.206.226.82 1 min ago 1x AWS(vCPU=4) READY us-east-1
http-server 5 2 3.26.232.31 1 min ago 1x AWS(vCPU=4) READY us-east-1
最终，与滚动更新一样，我们将只剩下新副本准备好为用户请求提供服务。
$ sky serve status http-server
Services
NAME VERSION UPTIME STATUS REPLICAS ENDPOINT
http-server 2 11m 42s READY 3/3 44.206.240.249:30002
Service Replicas
SERVICE_NAME ID VERSION IP LAUNCHED RESOURCES STATUS REGION
http-server 3 2 3.93.241.163 3 mins ago 1x AWS(vCPU=4) READY us-east-1
http-server 4 2 18.206.226.82 3 mins ago 1x AWS(vCPU=4) READY us-east-1
http-server 5 2 3.26.232.31 1 min ago 1x AWS(vCPU=4) READY us-east-1