Weird database exception:

There are mainly two abnormal sections as follows

1. Connection reset

The last packet successfully received from the server was 1 milliseconds ago.  The last packet sent successfully to the server was 1 milliseconds ago.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
	at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
	at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:556)
	at com.mysql.cj.protocol.a.NativeProtocol.checkErrorMessage(NativeProtocol.java:726)
	at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:665)
	at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:980)
	at com.mysql.cj.NativeSession.execSQL(NativeSession.java:1185)
	at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:952)
	... 34 common frames omitted
Caused by: java.net.SocketException: Connection reset
	at java.net.SocketInputStream.read(SocketInputStream.java:210)
	at java.net.SocketInputStream.read(SocketInputStream.java:141)
	at com.mysql.cj.protocol.ReadAheadInputStream.fill(ReadAheadInputStream.java:107)
	at com.mysql.cj.protocol.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:150)
	at com.mysql.cj.protocol.ReadAheadInputStream.read(ReadAheadInputStream.java:180)
	at java.io.FilterInputStream.read(FilterInputStream.java:133)
	at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64)
	at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:63)
	at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:45)
	at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:52)
	at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:41)
	at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:54)
	at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:44)
	at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:550)
	... 39 common frames omitted

2. Close stream spatiotemporal pointer

The last packet successfully received from the server was 4 milliseconds ago.  The last packet sent successfully to the server was 4 milliseconds ago.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
	at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
	at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:654)
	at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:980)
	at com.mysql.cj.NativeSession.execSQL(NativeSession.java:1185)
	at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:952)
	... 54 common frames omitted
Caused by: java.lang.NullPointerException: null
	at com.mysql.cj.protocol.a.NativeProtocol.clearInputStream(NativeProtocol.java:827)
	at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:646)
	... 57 common frames omitted

For example, questions 1 and 2 are finally located in the socket connection. So we need to locate the network problem.

Ideas:

1. Is there anti-virus software installed.

2. There is no firewall.

3. Do you use vip? Does vip often float. When we encounter this problem, we mainly modify the keepalive configuration. In the original keepalive log, a large number of free arp messages were changed from multicast to unicast. At the same time, we increased the tcp and tcpfin timeout of keepalive.