java.net.SocketTimeoutException: Read timed out under Tomcat

I have a Tomcat based web application. I am intermittently getting the following exception,

Caused by: java.net.SocketTimeoutException: Read timed out
	at java.net.SocketInputStream.socketRead0(Native Method)
	at java.net.SocketInputStream.read(SocketInputStream.java:150)
	at java.net.SocketInputStream.read(SocketInputStream.java:121)
	at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:532)
	at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:501)
	at org.apache.coyote.http11.InternalInputBuffer$InputStreamInputBuffer.doRead(InternalInputBuffer.java:563)
	at org.apache.coyote.http11.filters.IdentityInputFilter.doRead(IdentityInputFilter.java:124)
	at org.apache.coyote.http11.AbstractInputBuffer.doRead(AbstractInputBuffer.java:346)
	at org.apache.coyote.Request.doRead(Request.java:422)
	at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:290)
	at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:431)
	at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:315)
	at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:200)
	at java.nio.channels.Channels$ReadableByteChannelImpl.read(Channels.java:385)

Unfortunately I don't have access to the client, so I am just trying to confirm on various reasons this can happen,

1. Server is trying to read data from the request, but its taking longer than the timeout value for the data to arrive from the client. Timeout here would typically be Tomcat connector → connectionTimeout attribute.

2. Client has a read timeout set, and server is taking longer than that to respond.

3. One of the threads I went through, said this can happen with high concurrency and if the keepalive is enabled.

For #1, the initial value I had set was 20 sec, I have bumped this up to 60sec, will test, and see if there are any changes.

Meanwhile, if any of you guys can provide you expert opinion on this, that'l be really helpful. Or for that matter any other reason you can think of which might cause this issue.

> Server is trying to read data from the request, but its taking longer than the timeout value for the data to arrive from the client. Timeout here would typically be tomcat connector -> connectionTimeout attribute.

Correct.

> Client has a read timeout set, and server is taking longer than that to respond.

No. That would cause a timeout at the client.

> One of the threads i went through, said this can happen with high concurrency and if the keepalive is enabled.

That is obviously guesswork, and completely incorrect. It happens if and only if no data arrives within the timeout. Period. Load and keepalive and concurrency have nothing to do with it whatsoever.

It just means the client isn't sending. You don't need to worry about it. Browser clients come and go in all sorts of strange ways.

Here are the basic instructions:-

1. Locate the "server.xml" file in the "conf" folder beneath Tomcat's base directory (i.e. %CATALINA_HOME%/conf/server.xml).
2. Open the file in an editor and search for <Connector.
3. Locate the relevant connector that is timing out - this will typically be the HTTP connector, i.e. the one with protocol="HTTP/1.1".
4. If a connectionTimeout value is set on the connector, it may need to be increased - e.g. from 20000 milliseconds (= 20 seconds) to 120000 milliseconds (= 2 minutes). If no connectionTimeout property value is set on the connector, the default is 60 seconds - if this is insufficient, the property may need to be added.
5. Restart Tomcat

Connection.Response resp = Jsoup.connect(url) //
				.timeout(20000) //
				.method(Connection.Method.GET) //
				.execute();

actually, the error occurs when you have slow internet so try to maximize the timeout time and then your code will definitely work as it works for me.

I had the same problem while trying to read the data from the request body. In my case which occurs randomly only to the mobile-based client devices. So I have increased the connectionUploadTimeout to 1min as suggested by this link

I have the same issue. The java.net.SocketTimeoutException: Read timed out error happens on Tomcat under Mac 11.1, but it works perfectly in Mac 10.13. Same Tomcat folder, same WAR file. Have tried setting timeout values higher, but nothing I do works. If I run the same SpringBoot code in a regular Java application (outside Tomcat 9.0.41 (tried other versions too), then it works also.

Mac 11.1 appears to be interfering with Tomcat.

As another test, if I copy the WAR file to an AWS EC2 instance, it works fine there too.

Spent several days trying to figure this out, but cannot resolve.

Suggestions very welcome! :)

It means time out from your server response. It causes due to server config and internet response.

I am using 11.2 and received timeouts.

I resolved by using the version of jsoup below.

    <dependency>
        <groupId>org.jsoup</groupId>
        <artifactId>jsoup</artifactId>
        <version>1.7.2</version>
        <scope>compile</scope>
    </dependency>