Re: [pgsql-cluster-hackers] Replication over RDMA with Infiniband orRoCE

On 3/20/17 02:47, Greg Sabino Mullane wrote:
> On Fri, Mar 10, 2017 at 12:11:11PM +0800, DEV_OPS wrote:
>> we are going to implement the replication over RDMA with Infiniband
>>
>> the use case is target on high-end OLTP application , that requires NO
>> DATA LOST between master and slaves which in different locations or
>> cities, with HIGH PERFORMANCE REPLICATION with very LOW LATENCY (such as
>> in 'ns' or 'us', but not 'ms' or 's'), and robust, reliable and secure.
> A few more details are needed before we would be able to help you out.
> What exactly are your goals? Are you trying to implement this over
> Postgres' streaming replication system?
Yes, we are going to implement this over Postgres' streaming replication
system,
the usecase is DR, eg: the sync between two datacenter in same city,
there had FC link, (Now FC could be used to extend IB network, so we are
going to implement the native RDMA replication for low latency purpose
for that case-- it is very import for some critical system, also, this
replication is preferred base on Postgres' stream replication )

so, we are writing to here for advice/help for the design and implementation

we are going to plan following feature:

1.) compatible with current IP based stream replication system; but
also, need the IB native replication, so there is a parameter enable if
replication system use IP or IB

2.) the IB based replication system will work with current IP based
replication system, it mean that, in a replication system, maybe had IB
replication, and also had IP replication, the case1 is: NodeA to NodeB
to NodeC,  NodeA -IB->NodeB --IP-->NodeC ; means, NodeA to NodeB could
be IB base replication, it provide low latency ;     and NodeB to NodeC
it is based on IP, it's orig IP based replication system ;  the case2
is: NodeA--IB-->NodeB, NodeA--IP-->NodeC ; means NodeA to NodeB is IB
replication; and NodeA to NodeC is IP based replication,

3.) it will support sync replication and async replication ; also
support phy replication and logical replication .

4.) required rep system has robust, stable and high performance, low
latency.

5.) OS will support Linux and FreeBSD at least, possible Solaris X86
(currently, IB is supported on Linux and FreeBSD system, but for orig IB
support, Solaris was the best)


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