Hi Gianni,
On 08.04.2020 17:38, Gianni Milo wrote:
My understanding is the following...
- If you have 3 nodes, 2 of them Diskful (A,B) and 1 Diskless (C),
then if Primary is A or B, then there will be *one* write stream over
the the network (either from A -> B or B -> A), reads will be served
locally on each Diskful Primary node (if load-balancing is enabled
also over the network). Node C is ignored in this case.
If the Primary is the 3rd (Diskless) node (C), then there will be
*two* write streams going through the network (C -> A,B) and possibly
2 read streams depending if the load-balancing option is enabled or
not. This is probably the scenario you mentioned.
- If you have 3 (A,B,C) nodes and all of them are Diskful, then when
any of those nodes is in Primary mode there will be *two* write
streams going through the network(A -> B,C or B -> A,C or C -> A,B)
reads will be served locally on each Primary node (if load-balancing
is enabled also over the network). This is probably the scenario that
Robert mentioned.
Exactly. This is why multicast propagation, which can decrease PPS twice
[on particular node], can be kind of a silver bullet :-)
--
Volodymyr Litovka
"Vision without Execution is Hallucination." -- Thomas Edison
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