用Toxiproxy和Java的HttpURLConnection模拟各种连接问题，以查看产生了什么样的错误：连接超时vs.读取超时vs.连接被拒绝…。

结果：

系统：openjdk 11.0.1 2018-10-16

1. (.setConnectTimeout 1) => java.net.SocketTimeoutException：连接超时
2. (.setReadTimeout 1) => javax.net.ssl.SSLProtocolException: Read timed out在HTTPS上javax.net.ssl.SSLProtocolException: Read timed out ， java.net.SocketTimeoutException: Read timed out在HTTP上java.net.SocketTimeoutException: Read timed out （或Toxiproxy，延迟或超时为5s）
3. 在端口上没有监听=> java.net.ConnectException：连接被拒绝
4. 未配置上游的Toxiproxy（即，端口已打开，但连接没有问题）=> javax.net.ssl.SSLHandshakeException: Remote host terminated the handshake HTTPS上javax.net.ssl.SSLHandshakeException: Remote host terminated the handshake ， java.net.SocketTimeoutException: Read timed out HTTP java.net.SocketTimeoutException: Read timed out
5. limit_data_downstream => java.io.IOException：过早的EOF

（我还无法模拟（但）是“连接中断/断开”。）

设置

先决条件

要在/etc/hosts添加：

127.0.0.1       proxied.google.com

毒物替代品设置

开始使用抗氧化剂：

docker pull shopify/toxiproxy
# BEFORE we `run` it: case #3
docker run --rm -p 5555:5555 -p 6666:6666 -p 8474:8474 --name toxiproxy -it shopify/toxiproxy

配置它（我们可以只发布到:8474但是使用CLI更容易）：

$ docker exec -it toxiproxy /bin/sh
/ # cd /go/bin/
# ./toxiproxy-cli create google -l 0.0.0.0:6666 -u www.google.com:443 # BEFORE this is run: case #4
# ./toxiproxy-cli toxic add google -t latency -a latency=5000 # case #2
Added downstream latency toxic 'latency_downstream' on proxy 'google
# ./toxiproxy-cli toxic remove google -n latency_downstream
Removed toxic 'latency_downstream' on proxy 'google'# ./toxiproxy-cli toxic add google -t  timeout -a timeout=2000 # case #2
Added downstream timeout toxic 'timeout_downstream' on proxy 'google'
# ./toxiproxy-cli toxic remove google -n timeout_downstream
Removed toxic 'timeout_downstream' on proxy 'google'# ./toxiproxy-cli toxic add google -t limit_data -a bytes=5000 # case #5
Added downstream limit_data toxic 'limit_data_downstream' on proxy 'google'

测试代码

(import '[java.net URL HttpURLConnection])
(->(doto ^HttpURLConnection (.openConnection (URL. "https://proxied.google.com:6666/"));; BEWARE: JVM *must* be started with `-Dsun.net.http.allowRestrictedHeaders=true` to allow setting the Host:(.setRequestProperty "Host" "www.google.com")(.setConnectTimeout 1000)(.setReadTimeout 1000))(.getInputStream)slurp)

巴克特

阅读我的toxiproxy模拟网络超时以了解为什么我们需要打扰/etc/hosts和Host标头。

翻译自: https://www.javacodegeeks.com/2018/11/java-simulating-connection-problems.html