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The documentation states that the DataHeader::unscheduledIndexLimit is the number of packets that "will be sent" without a grant. However, Sender::sendMessage() sets this value to be the max number of packets that "might" be sent. This mismatch can lead the Receiver to expect more unscheduled packets than there are packets in the message which in turn may cause RESEND requests for nonexistent packets. The current implementation ignores these "inconsistent" RESEND request with a warning message and thus the issue doesn't result in an application visible error.

The implementation should be fixed so that both the Sender and Receiver use a consistent definition of unscheduledIndexLimit.

For example, perhaps they don't need to be tracked by the MessageBucket at all.

Hi,
I read the paper in sigcomm 2018 about Homa. And I also check the codes roughly in this repo.
I have many problems about this implementation.
For example, in Homa/src/Protocol.h, there is nothing about priority in Grant or Data packet Header.
I also check the Homa/src/Sender.cc , I find in Sender::sendMessage function, the packets are sent without any consideration about priority (the priority is just set to 0 in line 119).
Also in Homa/src/Receiver.cc, it seems there is nothing about processing priority when send GRANT packets.

So Is this implementation far away about what described in the paper sigcomm 2018 or I check wrong places ?
Does this implementation is the final version used in the paper?

Expect your reply
Thanks!

It is in the critical path of sending small messages. Similarly, signalNewMessage() is in the critical path of receiving small messages.

I'm searching a good transport protocol.
I wanna know more about homa, like whether there's a finished version.

Hi,

Thank you for providing DPDK implementation of Homa. It is really helpful.

There are several issues I met.

1. I used DPDK 18.11 and cmake 3.15 to build the code. I got this compile error and I am not sure if I missed something:

/home/qizhe/Homa/src/Drivers/DPDK/DpdkDriver.cc: In constructor ‘Homa::Drivers::DPDK::DpdkDriver::DpdkDriver(int, int, char**, const Homa::Drivers::DPDK::DpdkDriver::Config*)’: /home/qizhe/Homa/src/Drivers/DPDK/DpdkDriver.cc:96:54: error: expected ‘,’ before ‘)’ token static_assert(sizeof(members) == sizeof(Internal));

2. I notice in Read-me, it says this implementation is incomplete. But can I still use this code to run some basic test-case? eg. I have 8 servers and simply want to run Homa among these 8 servers.

3. In the Read-me, the second step for build is cmake -E chdir build; it should be sudo cmake -E chdir build cmake ..?