Base url health check for gadgets has been failed for JIRA core 7.3.3.

[Deleted user]

We have tried all possible ways to fix it except authentication of proxy and added license too.
Our outbound response is passing through proxy and all in-bound requests are resolving to the correct server through reverse proxy

getting the following error from stack-trace:

ERROR [c.a.j.p.healthcheck.support.BaseUrlHealthCheck] An error occurred when performing the Base URL healthcheck:
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:170)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:139)
at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:155)
at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:284)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:167)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
at com.atlassian.jira.plugins.healthcheck.support.BaseUrlHealthCheck.doCheck(BaseUrlHealthCheck.java:52)
at com.atlassian.jira.plugins.healthcheck.support.AbstractSupportHealthCheck.check(AbstractSupportHealthCheck.java:27)
at com.atlassian.support.healthcheck.impl.PluginSuppliedSupportHealthCheck.check(PluginSuppliedSupportHealthCheck.java:41)
at com.atlassian.support.healthcheck.thread.HealthCheckCallable.call(HealthCheckCallable.java:32)
at com.atlassian.support.healthcheck.thread.HealthCheckCallable.call(HealthCheckCallable.java:15)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

[Nic Brough -Adaptavist-]

What is the base url set to, and can the Server resolve it on the command line (check with curl or wget)?