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Posted to users@tomcat.apache.org by Tejas Nandanikar <te...@gmail.com> on 2016/05/12 05:16:10 UTC
A question regarding websocket implementation of Apache Tomcat 8.0.33
I am using Apache Tomcat 8.0.33.
I was going through Java documentation about RemoteEndpoint.Basic
which says that sendText(String text) blocks until all of the message
has been transmitted.
But I noticed that when the client loses internet connection and
sendText() method is called on the server side, it doesn't thrown an
IOException immediately and the method returns normally.
IOException is thrown later and the onError() method is called. Is
this a normal behaviour? Shouldn't the sendText() method block until
all the message has been transmitted successfully or throw an
IOException immediately if there's any problem?
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Re: A question regarding websocket implementation of Apache Tomcat 8.0.33
Posted by Tejas Nandanikar <te...@gmail.com>.
Isn't there any workaround to this situation? In my application, a
database update operation depends on whether the message was delivered
to the client or not, so in that scenario, I would never know if the
message was delivered. And even if onError() is called later, I can
never know which message caused IOException.
On Thu, May 12, 2016 at 1:09 PM, Mark Thomas <ma...@apache.org> wrote:
> On 12/05/2016 08:24, Tejas Nandanikar wrote:
>> Thank you for your quick reply.
>> So consider a case where client abruptly loses internet connection.
>> In that scenario, the sendText() would return normally as the server
>> hasn't received 'close' packet from the client, did I get it right?
>
> Assuming that the message was small enough to fit completely into the
> network buffers, yes.
>
> Mark
>
>>
>> On Thu, May 12, 2016 at 12:43 PM, Mark Thomas <ma...@apache.org> wrote:
>>> On 12/05/2016 06:16, Tejas Nandanikar wrote:
>>>> I am using Apache Tomcat 8.0.33.
>>>> I was going through Java documentation about RemoteEndpoint.Basic
>>>> which says that sendText(String text) blocks until all of the message
>>>> has been transmitted.
>>>> But I noticed that when the client loses internet connection and
>>>> sendText() method is called on the server side, it doesn't thrown an
>>>> IOException immediately and the method returns normally.
>>>> IOException is thrown later and the onError() method is called. Is
>>>> this a normal behaviour?
>>>
>>> Yes.
>>>
>>>> Shouldn't the sendText() method block until
>>>> all the message has been transmitted successfully or throw an
>>>> IOException immediately if there's any problem?
>>>
>>> Only if the server knows there is a problem at that point. Depending on
>>> how the client disconnects, there server might not know and the message
>>> will sit in the network buffer until the network stack figures out that
>>> the client has gone away.
>>>
>>> Mark
>>>
>>>
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>>> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
>>> For additional commands, e-mail: users-help@tomcat.apache.org
>>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
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>>
>
>
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Re: A question regarding websocket implementation of Apache Tomcat
8.0.33
Posted by Mark Thomas <ma...@apache.org>.
On 12/05/2016 08:24, Tejas Nandanikar wrote:
> Thank you for your quick reply.
> So consider a case where client abruptly loses internet connection.
> In that scenario, the sendText() would return normally as the server
> hasn't received 'close' packet from the client, did I get it right?
Assuming that the message was small enough to fit completely into the
network buffers, yes.
Mark
>
> On Thu, May 12, 2016 at 12:43 PM, Mark Thomas <ma...@apache.org> wrote:
>> On 12/05/2016 06:16, Tejas Nandanikar wrote:
>>> I am using Apache Tomcat 8.0.33.
>>> I was going through Java documentation about RemoteEndpoint.Basic
>>> which says that sendText(String text) blocks until all of the message
>>> has been transmitted.
>>> But I noticed that when the client loses internet connection and
>>> sendText() method is called on the server side, it doesn't thrown an
>>> IOException immediately and the method returns normally.
>>> IOException is thrown later and the onError() method is called. Is
>>> this a normal behaviour?
>>
>> Yes.
>>
>>> Shouldn't the sendText() method block until
>>> all the message has been transmitted successfully or throw an
>>> IOException immediately if there's any problem?
>>
>> Only if the server knows there is a problem at that point. Depending on
>> how the client disconnects, there server might not know and the message
>> will sit in the network buffer until the network stack figures out that
>> the client has gone away.
>>
>> Mark
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
>> For additional commands, e-mail: users-help@tomcat.apache.org
>>
>
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Re: A question regarding websocket implementation of Apache Tomcat 8.0.33
Posted by Tejas Nandanikar <te...@gmail.com>.
Thank you for your quick reply.
So consider a case where client abruptly loses internet connection.
In that scenario, the sendText() would return normally as the server
hasn't received 'close' packet from the client, did I get it right?
On Thu, May 12, 2016 at 12:43 PM, Mark Thomas <ma...@apache.org> wrote:
> On 12/05/2016 06:16, Tejas Nandanikar wrote:
>> I am using Apache Tomcat 8.0.33.
>> I was going through Java documentation about RemoteEndpoint.Basic
>> which says that sendText(String text) blocks until all of the message
>> has been transmitted.
>> But I noticed that when the client loses internet connection and
>> sendText() method is called on the server side, it doesn't thrown an
>> IOException immediately and the method returns normally.
>> IOException is thrown later and the onError() method is called. Is
>> this a normal behaviour?
>
> Yes.
>
>> Shouldn't the sendText() method block until
>> all the message has been transmitted successfully or throw an
>> IOException immediately if there's any problem?
>
> Only if the server knows there is a problem at that point. Depending on
> how the client disconnects, there server might not know and the message
> will sit in the network buffer until the network stack figures out that
> the client has gone away.
>
> Mark
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
>
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Re: A question regarding websocket implementation of Apache Tomcat
8.0.33
Posted by Mark Thomas <ma...@apache.org>.
On 12/05/2016 06:16, Tejas Nandanikar wrote:
> I am using Apache Tomcat 8.0.33.
> I was going through Java documentation about RemoteEndpoint.Basic
> which says that sendText(String text) blocks until all of the message
> has been transmitted.
> But I noticed that when the client loses internet connection and
> sendText() method is called on the server side, it doesn't thrown an
> IOException immediately and the method returns normally.
> IOException is thrown later and the onError() method is called. Is
> this a normal behaviour?
Yes.
> Shouldn't the sendText() method block until
> all the message has been transmitted successfully or throw an
> IOException immediately if there's any problem?
Only if the server knows there is a problem at that point. Depending on
how the client disconnects, there server might not know and the message
will sit in the network buffer until the network stack figures out that
the client has gone away.
Mark
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