pushy: InternalServerError from APNs

We are using Pushy in our production environment and it works great! Besides we have a staging environment where tests are performed prior to launching new versions. Staging environment is not always used and most of the time it is in idle state. Today when we started to use staging, we got InternalServerError errors (stack trace given below). I guess it is related to long idle state of pushy, not sure though. We didn’t have any choice but to restart the app.

In which cases APNs may return such an error? Should pushy be closing and reconnecting in such cases? Or is it a duty of our side to reconnect upon such an error?

Using pushy v0.9, java 1.8.0_102 (Oracle)

2017-01-06 05:23:27,715  WARN [nioEventLoopGroup-2-4] c.r.p.a.ApnsClient APNs server reported an internal error when sending ... .
2017-01-06 05:23:27,715 ERROR [nioEventLoopGroup-2-4] o.g.g.a.ApnsResponseListener Failed to send notification id=117_963041067
java.util.concurrent.ExecutionException: com.relayrides.pushy.apns.ApnsServerException: {"reason":"InternalServerError"}
    at io.netty.util.concurrent.AbstractFuture.get(AbstractFuture.java:54)
    at org.grouvi.gpns.apns.ApnsResponseListener.operationComplete(ApnsResponseListener.java:59)
    at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:514)
    at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:507)
    at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:486)
    at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:427)
    at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:129)
    at com.relayrides.pushy.apns.ApnsClient.handleServerError(ApnsClient.java:965)
    at com.relayrides.pushy.apns.ApnsClientHandler$ApnsClientHandlerFrameAdapter.onDataRead(ApnsClientHandler.java:173)
    at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onDataRead(DefaultHttp2ConnectionDecoder.java:229)
    at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readDataFrame(DefaultHttp2FrameReader.java:411)
    at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:245)
    at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:155)
    at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
    at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:335)
    at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:395)
    at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:411)
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:373)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:351)
    at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:266)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:373)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:351)
    at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1069)
    at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:902)
    at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:411)
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:373)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:351)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:373)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:129)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:651)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:574)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:488)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:450)
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:873)
    at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
    at java.lang.Thread.run(Thread.java:745)
Caused by: com.relayrides.pushy.apns.ApnsServerException: {"reason":"InternalServerError"}
    ... 37 common frames omitted