connectTimeout in okhttp3 slows down responnse time - performance

Question

Ho All,
I have a odd issue with okhttp version 4.9.0. It seems to increase the response time ( client.newCall(request).execute() ). If I increase the connectTimeout to 5 seconds the response time increases to 6 if I increase it to 15 seconds the response time increases to 16 seconds. Below is how I am using the builder.
client = new OkHttpClient.Builder()
.connectionPool(new ConnectionPool(2, 2, TimeUnit.SECONDS))
.cache(null)
.connectTimeout(2, TimeUnit.SECONDS)
.readTimeout(25, TimeUnit.SECONDS).build();
Thanks for any hints!

Answer 1

It is likely getting two or more routes and failing to connect to the first before the second one works. Most likely you have anetwork problem or similar and should fix that.
To confirm add a debugging EventListener
https://square.github.io/okhttp/events/
Since you haven't provided a useful reproduction, we can simulate using an additional route to test against.
val client = OkHttpClient.Builder()
.dns(object: Dns {
override fun lookup(hostname: String): List<InetAddress> {
return listOf<InetAddress>(InetAddress.getByName("198.51.100.0")) + Dns.SYSTEM.lookup("httpbin.org")
}
})
.eventListenerFactory(LoggingEventListener.Factory())
.build()
val response = client.newCall(Request.Builder().url("https://httpbin.org/get").build()).execute()
println(response.body!!.string())
Output will be like the following, not that the first connect takes 10 seconds (the connect timeouts) as it's hitting a dummy IP and then subsequent connections will try the second of the total 5 available IP addresses successfully and the request will continue.
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [0 ms] callStart: Request{method=GET, url=https://httpbin.org/get}
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [34 ms] proxySelectStart: https://httpbin.org/
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [35 ms] proxySelectEnd: [DIRECT]
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [36 ms] dnsStart: httpbin.org
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [150 ms] dnsEnd: [/198.51.100.0, httpbin.org/3.211.1.78, httpbin.org/35.170.225.136, httpbin.org/34.198.212.59, httpbin.org/52.6.34.179]
Nov 23, 2020 7:44:01 AM okhttp3.internal.platform.Platform log
INFO: [153 ms] connectStart: /198.51.100.0:443 DIRECT
Nov 23, 2020 7:44:11 AM okhttp3.internal.platform.Platform log
INFO: [10164 ms] connectFailed: null java.net.SocketTimeoutException: Connect timed out
Nov 23, 2020 7:44:11 AM okhttp3.internal.platform.Platform log
INFO: [10165 ms] connectStart: httpbin.org/3.211.1.78:443 DIRECT
Nov 23, 2020 7:44:11 AM okhttp3.internal.platform.Platform log
INFO: [10263 ms] secureConnectStart
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10663 ms] secureConnectEnd: Handshake{tlsVersion=TLS_1_2 cipherSuite=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 peerCertificates=[CN=httpbin.org, CN=Amazon, OU=Server CA 1B, O=Amazon, C=US, CN=Amazon Root CA 1, O=Amazon, C=US] localCertificates=[]}
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10676 ms] connectEnd: h2
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10678 ms] connectionAcquired: Connection{httpbin.org:443, proxy=DIRECT hostAddress=httpbin.org/3.211.1.78:443 cipherSuite=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 protocol=h2}
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10679 ms] requestHeadersStart
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10683 ms] requestHeadersEnd
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10903 ms] responseHeadersStart
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10904 ms] responseHeadersEnd: Response{protocol=h2, code=200, message=, url=https://httpbin.org/get}
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10907 ms] responseBodyStart
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10908 ms] responseBodyEnd: byteCount=272
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10908 ms] connectionReleased
Nov 23, 2020 7:44:12 AM okhttp3.internal.platform.Platform log
INFO: [10908 ms] callEnd
{
"args": {},
"headers": {
"Accept-Encoding": "gzip",
"Host": "httpbin.org",
"User-Agent": "okhttp/4.10.0-RC1",
"X-Amzn-Trace-Id": "Root=1-5fbb684d-0b7fa68f2cce945f25b5f1bf"
},
"origin": "81.100.210.134",
"url": "https://httpbin.org/get"
}

Answer 2

I ended up using a solution for Android mobile (smart device) when compiling to be compatible with java 1.8. Just add the below to your gradle.build file under defaultConfig section for the module where you use okhttp.
android.compileOptions.sourceCompatibility 1.8
android.compileOptions.targetCompatibility 1.8