NLnet task 3 #667

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lx merged 60 commits from nlnet-task3 into next-0.10 2024-01-11 10:58:08 +00:00
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@ -143,7 +143,7 @@ impl<F: TableSchema, R: TableReplication> Table<F, R> {
self.data.queue_insert(tx, e)
}
pub async fn insert_many<I, IE>(&self, entries: I) -> Result<(), Error>
pub async fn insert_many<I, IE>(self: &Arc<Self>, entries: I) -> Result<(), Error>
where
I: IntoIterator<Item = IE> + Send + Sync,
IE: Borrow<F::E> + Send + Sync,
@ -161,52 +161,149 @@ impl<F: TableSchema, R: TableReplication> Table<F, R> {
Ok(())
}
async fn insert_many_internal<I, IE>(&self, entries: I) -> Result<(), Error>
async fn insert_many_internal<I, IE>(self: &Arc<Self>, entries: I) -> Result<(), Error>
where
I: IntoIterator<Item = IE> + Send + Sync,
IE: Borrow<F::E> + Send + Sync,
{
let mut call_list: HashMap<_, Vec<_>> = HashMap::new();
// The different items will have to be stored on possibly different nodes.
// We will here batch all items into a single request for each concerned
// node, with all of the entries it must store within that request.
// Each entry has to be saved to a specific list of "write sets", i.e. a set
// of node within wich a quorum must be achieved. In normal operation, there
// is a single write set which corresponds to the quorum in the current
// cluster layout, but when the layout is updated, multiple write sets might
// have to be handled at once. Here, since we are sending many entries, we
// will have to handle many write sets in all cases. The algorihtm is thus
// to send one request to each node with all the items it must save,
// and keep track of the OK responses within each write set: if for all sets
// a quorum of nodes has answered OK, then the insert has succeeded and
// consistency properties (read-after-write) are preserved.
// Some code here might feel redundant with RpcHelper::try_write_many_sets,
// but I think deduplicating could lead to more spaghetti instead of
// improving the readability, so I'm leaving as is.
let quorum = self.data.replication.write_quorum();
// Serialize all entries and compute the write sets for each of them.
// In the case of sharded table replication, this also takes an "ack lock"
// to the layout manager to avoid ack'ing newer versions which are not
// taken into account by writes in progress (the ack can happen later, once
// all writes that didn't take the new layout into account are finished).
// These locks are released when entries_vec is dropped, i.e. when this
// function returns.
let mut entries_vec = Vec::new();
for entry in entries.into_iter() {
let entry = entry.borrow();
let hash = entry.partition_key().hash();
// TODO: use write sets
let who = self.data.replication.storage_nodes(&hash);
let write_sets = self.data.replication.write_sets(&hash);
let e_enc = Arc::new(ByteBuf::from(entry.encode()?));
for node in who {
call_list.entry(node).or_default().push(e_enc.clone());
entries_vec.push((write_sets, e_enc));
}
// Compute a deduplicated list of all of the write sets,
// and compute an index from each node to the position of the sets in which
// it takes part, to optimize the detection of a quorum.
let mut write_sets = entries_vec
.iter()
.map(|(wss, _)| wss.as_ref().iter().map(|ws| ws.as_slice()))
.flatten()
.collect::<Vec<&[Uuid]>>();
write_sets.sort();
write_sets.dedup();
let mut write_set_index = HashMap::<&Uuid, Vec<usize>>::new();
for (i, write_set) in write_sets.iter().enumerate() {
for node in write_set.iter() {
write_set_index.entry(node).or_default().push(i);
}
}
let call_futures = call_list.drain().map(|(node, entries)| async move {
let rpc = TableRpc::<F>::Update(entries);
// Build a map of all nodes to the entries that must be sent to that node.
let mut call_list: HashMap<Uuid, Vec<_>> = HashMap::new();
for (write_sets, entry_enc) in entries_vec.iter() {
for write_set in write_sets.as_ref().iter() {
for node in write_set.iter() {
call_list.entry(*node).or_default().push(entry_enc.clone())
}
}
}
let resp = self
.system
.rpc_helper()
.call(
&self.endpoint,
node,
rpc,
RequestStrategy::with_priority(PRIO_NORMAL),
)
.await?;
Ok::<_, Error>((node, resp))
// Build futures to actually perform each of the corresponding RPC calls
let call_count = call_list.len();
let call_futures = call_list.into_iter().map(|(node, entries)| {
let this = self.clone();
let tracer = opentelemetry::global::tracer("garage");
let span = tracer.start(format!("RPC to {:?}", node));
let fut = async move {
let rpc = TableRpc::<F>::Update(entries);
let resp = this
.system
.rpc_helper()
.call(
&this.endpoint,
node,
rpc,
RequestStrategy::with_priority(PRIO_NORMAL).with_quorum(quorum),
)
.await;
(node, resp)
};
fut.with_context(Context::current_with_span(span))
});
// Run all requests in parallel thanks to FuturesUnordered, and collect results.
let mut resps = call_futures.collect::<FuturesUnordered<_>>();
let mut set_counters = vec![(0, 0); write_sets.len()];
let mut successes = 0;
let mut errors = vec![];
while let Some(resp) = resps.next().await {
if let Err(e) = resp {
errors.push(e);
while let Some((node, resp)) = resps.next().await {
match resp {
Ok(_) => {
successes += 1;
for set in write_set_index.get(&node).unwrap().iter() {
set_counters[*set].0 += 1;
}
}
Err(e) => {
errors.push(e);
for set in write_set_index.get(&node).unwrap().iter() {
set_counters[*set].1 += 1;
}
}
}
if set_counters.iter().all(|(ok_cnt, _)| *ok_cnt >= quorum) {
// Success
// Continue all other requests in background
tokio::spawn(async move {
resps.collect::<Vec<(Uuid, Result<_, _>)>>().await;
});
return Ok(());
}
if set_counters
.iter()
.enumerate()
.any(|(i, (_, err_cnt))| err_cnt + quorum > write_sets[i].len())
{
// Too many errors in this set, we know we won't get a quorum
break;
}
}
if errors.len() > self.data.replication.max_write_errors() {
Err(Error::Message("Too many errors".into()))
} else {
Ok(())
}
// Failure, could not get quorum within at least one set
let errors = errors.iter().map(|e| format!("{}", e)).collect::<Vec<_>>();
Err(Error::Quorum(
quorum,
Some(write_sets.len()),
successes,
call_count,
errors,
))
}
pub async fn get(