Mariano Guerra
Namespaced Key-Value Store
Replicated to all nodes
Eventually
Asynchronously
In memory (ETS)
On disk (DETS)
Local Read/Writes
Make riak_core run on windows
Per user Rate Limiting
Per Bucket/Key Eviction
Grep?
Follow calls?
Visualizations helps
Yak shaving: erlplorer
Problem
Vocabulary
Alternatives
Previous Work
Related Theory
Tradeoffs
High Level Design
"Benchmarks"
99 papers on the pile, take one, read it, follow the references, 123 papers on the pile...
Alvaro Videla's Syndrome
Achievement Unlocked
rebar3 new rebar3_riak_core tanodb # add recon dependency to rebar.config make devrel # in different consoles make dev1-console make dev2-console make dev3-console
make devrel-join make devrel-status make devrel-cluster-plan make devrel-cluster-commit make devrel-status
Using recon on the 3 nodes:
Trace all riak_core_metadata modules
Ignore lazy_tick messages
Log call params and returns
ReturnTrace = fun(_) -> return_trace() end. % at most 1000 calls per second Rate = {1000, 1000}. recon_trace:calls([{riak_core_broadcast, '_', fun ([A, _]) when A /= lazy_tick -> return_trace() end}, {riak_core_metadata_hashtree, '_', ReturnTrace}, {riak_core_metadata_object, '_', ReturnTrace}, {riak_core_metadata_manager, '_', ReturnTrace}, {riak_core_metadata_exchange_fsm, '_', ReturnTrace}, {riak_core_metadata, '_', ReturnTrace}], Rate).
Write something in riak_core_metadata:
FullPrefix = {<<"tanodb">>, <<"mymeta">>}. MDKey = my_key_1. MDValue = <<"my metadata value">>. riak_core_metadata:put(FullPrefix, MDKey, MDValue).
When the dust settles:
recon_trace:clear().
Store logs from 3 nodes
Annotate trace calls and returns
Follow code from the traces
Copy code simplify and inline it
Draw sequence diagrams
Draw state diagrams (for FSMs)
Understanding code is hard
Switch strategies when stuck
Approaches reinforce each other
Be organized with your notes
Try your own
We need more tooling
Implementation of paper Epidemic Broadcast Trees
Known as Plumtree
Eager Set
Lazy Set
Seen Msgs
How does node 3 gets the values broadcasted while he was down?
Tree in which every non-leaf node is labelled with the hash of the labels or values (in case of leaves) of its child nodes
Git
IPFS
ZFS, Btrfs
BitTorrent
Bitcoin, Ethereum
Cassandra, Riak
Insert
Update
Compare