adding rsockets support into JDK

[Lu, Yingqi]

Hi All,

I just created a CSR at the meantime. The link is available at https://bugs.openjdk.java.net/browse/JDK-8205186.

Please review this and let me know your feedback.

Thank you!
Lucy

>-----Original Message-----
>From: nio-dev [mailto:nio-dev-bounces at openjdk.java.net] On Behalf Of Lu,
>Yingqi
>Sent: Saturday, June 16, 2018 11:59 PM
>To: Alan Bateman <Alan.Bateman at oracle.com>; nio-dev at openjdk.java.net
>Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Aundhe, Shirish
><shirish.aundhe at intel.com>; Kaczmarek, Eric <eric.kaczmarek at intel.com>
>Subject: RE: adding rsockets support into JDK
>
>Hi All,
>
>Here is the webrev.05 version of the patch:
>http://cr.openjdk.java.net/~ylu/8195160.05/
>
>In this version, I did following changes:
>
>1. Fixed a small bug inside RdmaSocketImpl.GetOption.
>2. Took a subset of test cases from java.net.Socket, java.net.ServerSocket,
>java.nio.channels.SocketChannel, java.nio.channels.ServerSocketChannel and
>java.nio.channels.Selector tests and modified them for RDMA based sockets,
>channels and selectors.
>
>I am still working on test cases for the 3 new RDMA socket options and will
>submit webrev.06 on Monday. At the meantime, please let me know your
>feedback and comments on the current test cases.
>
>Thanks,
>Lucy
>
>>-----Original Message-----
>>From: Lu, Yingqi
>>Sent: Thursday, June 7, 2018 2:06 PM
>>To: 'Lu, Yingqi' <yingqi.lu at intel.com>; Alan Bateman
>><Alan.Bateman at oracle.com>; nio-dev at openjdk.java.net
>>Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Aundhe,
>>Shirish <shirish.aundhe at intel.com>; Kaczmarek, Eric
>><eric.kaczmarek at intel.com>
>>Subject: RE: adding rsockets support into JDK
>>
>>Hi Alan,
>>
>>I checked on librdmacm availability on different Linux distros. It is
>>at least available in Ubuntu, Arch Linux, Fedora/Centos/Red Hat, openSUSE and
>Gentoo.
>>
>>Thanks,
>>Lucy
>>
>>>-----Original Message-----
>>>From: nio-dev [mailto:nio-dev-bounces at openjdk.java.net] On Behalf Of
>>>Lu, Yingqi
>>>Sent: Thursday, June 7, 2018 11:11 AM
>>>To: Alan Bateman <Alan.Bateman at oracle.com>; nio-dev at openjdk.java.net
>>>Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Aundhe,
>>>Shirish <shirish.aundhe at intel.com>; Kaczmarek, Eric
>>><eric.kaczmarek at intel.com>
>>>Subject: RE: adding rsockets support into JDK
>>>
>>>Hi Alan,
>>>
>>>Thank you very much for your guidance on the tests. This is very helpful.
>>>
>>>I will look into SDP test cases and use them as a reference.
>>>
>>>In addition, I tested rsocket client and server on the same machine
>>>for both sockets and socket channels. InetAddress.getLocalHost() is
>>>used as the address for both server and client. The tests pass. Using
>>>sar[1], I see CPU cores are busy, but network does not show traffic. I
>>>think it might due to how rsocket handles local traffic (rsocket does
>>>not use loopback device). I also tested the same programs on two
>>>different machines and I saw network traffic shown on the RDMA network card.
>>>
>>>Thanks,
>>>Lucy
>>>
>>>[1] https://linux.die.net/man/1/sar
>>>
>>>
>>>>-----Original Message-----
>>>>From: Alan Bateman [mailto:Alan.Bateman at oracle.com]
>>>>Sent: Thursday, June 7, 2018 1:15 AM
>>>>To: Lu, Yingqi <yingqi.lu at intel.com>; nio-dev at openjdk.java.net
>>>>Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Aundhe,
>>>>Shirish <shirish.aundhe at intel.com>; Kaczmarek, Eric
>>>><eric.kaczmarek at intel.com>
>>>>Subject: Re: adding rsockets support into JDK
>>>>
>>>>On 05/06/2018 07:17, Lu, Yingqi wrote:
>>>>> Hi All,
>>>>>
>>>>> Here is the version #4 of the patch
>>>>> http://cr.openjdk.java.net/~ylu/8195160.04/
>>>>>
>>>>> In this version, I have changed:
>>>>>
>>>>> 1. Remove jdk.net.RdmaSocketImplFactory.
>>>>> 2. Remove the inheritance from
>>>>> SocketChannelImpl/ServerSocketChannelImpl,
>>>>replace it with SocketChannel/ServerSocketChannel.
>>>>> 3. Remove unnecessary setters from SocketImpl.
>>>>> 4. Override accept method to the ServerSocket returned by
>>>>jdk.net.openServerSocket.
>>>>> 5. Add a small comment to PollSelectorImpl.poll method 6. Clean up
>>>>> a little in Lib-jdk.net.gmk
>>>>>
>>>>> I am still working on creating all the test cases. Do we need to
>>>>> replicate all the
>>>>tests from both Socket/ServerSocket and
>>>>SocketChannel/ServerSocketChannel,
>>>>or we only need to pick up a subset of the cases?
>>>>>
>>>>> Please review the patch and let me know your feedback and comments.
>>>>>
>>>>For tests then I think we should have a basic set of tests that
>>>>exercise each of the elements in the API. For each socket and channel
>>>>type then each of the methods in the API should be exercised. There
>>>>are several new socket options so they should be exercised too. So a
>>>>good start is a maintainable set of unit tests. I don't think you
>>>>should be concerned with duplicating all the existing tests as many
>>>>of those tests are regression tests or stress specific areas where
>>>>there were bugs in the
>>>past.
>>>>
>>>>In general, I think testing is going to be a challenge for this
>>>>feature as it needs commitment to maintain the infrastructure needed
>>>>to test this feature and then running the tests at each release. When
>>>>we added the SDP support, it required maintaining a set of machines
>>>>with Infiniband HCAs and running the tests on a regular basis. I
>>>>assume something
>>>similar will be needed here.
>>>>
>>>>When developing the jtreg tests then it's important that don't fail
>>>>on systems without RDMA hardware. For SDP, the tests checked for
>>>>/proc/net/sdp and would pass silently when not present. I hope there
>>>>is something easy to check for rsockets.
>>>>
>>>>One thing that isn't clear to me is whether communication between
>>>>using sockets on the same machine, using an address plumbed to an
>>>>RDMA interface, will use the network or not. I guess I'm asking if
>>>>you are thinking about functional testing with two or more machines,
>>>>I assume you will at least be doing some of that when getting
>>>>performance data and
>>>comparing it to TCP or SDP connections.
>>>>
>>>>On the build changes, then one thing that would be useful to know is
>>>>whether librdmacm is included in all distributions. If someone is
>>>>building on say Ubuntu will they need to install an additional
>>>>package installed. I bring this as we may need to do a bit more on
>>>>the build to probe for the library. In other areas, at least in the
>>>>past, we've had to resort to dynamic linking (dlopen/dlsym). I'm sure
>>>>we should do that here, instead I'm just wondering whether the
>>>>rsocket support will be compiled in
>>>when there it is not present on the build machine.
>>>>
>>>>I skimmed quickly through the webrev and I think it's looking quite good.
>>>>RdmaNet defines only static methods so I don't think it needs to extends Net.
>>>>There is more to do on the javadoc for the new methods, also
>>>>RdmaSocketOptions. I can help out on that when the time comes.
>>>>
>>>>-Alan.
>>>>