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use std::collections::HashSet;
use std::marker::PhantomData;
use std::mem;
use std::net::SocketAddr;
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};
use std::thread;
use std::time::{Duration, Instant};
use dns;
use backoff::Backoff;
use itertools::Itertools;
use protobuf::Message;
use queue_map::QueueMap;
use rpc::{
Callback,
Messenger,
Rpc,
master
};
use util;
use Error;
use MasterError;
use MasterErrorCode;
use MasterId;
use RaftRole;
use Result;
use Status;
use parking_lot::Mutex;
use kudu_pb::consensus_metadata::{RaftPeerPB_Role as Role};
use kudu_pb::master::{
AlterTableRequestPB, AlterTableResponsePB,
CreateTableRequestPB, CreateTableResponsePB,
DeleteTableRequestPB, DeleteTableResponsePB,
GetTableLocationsRequestPB, GetTableLocationsResponsePB,
GetTableSchemaRequestPB, GetTableSchemaResponsePB,
GetTabletLocationsRequestPB, GetTabletLocationsResponsePB,
IsAlterTableDoneRequestPB, IsAlterTableDoneResponsePB,
IsCreateTableDoneRequestPB, IsCreateTableDoneResponsePB,
ListMastersRequestPB, ListMastersResponsePB,
ListTablesRequestPB, ListTablesResponsePB,
ListTabletServersRequestPB, ListTabletServersResponsePB,
PingRequestPB, PingResponsePB,
};
use kudu_pb::wire_protocol::{ServerEntryPB as MasterEntry};
const QUEUE_LEN: usize = 256;
const LEADER_REFRESH_TIMEOUT_SECS: u64 = 60;
macro_rules! impl_master_rpc {
($fn_name:ident, $request_type:ident, $response_type:ident) => {
pub fn $fn_name<F>(&self, deadline: Instant, request: $request_type, cb: F)
where F: FnOnce(Result<$response_type>) + Send + 'static {
let addr = util::dummy_addr();
let mut rpc = master::$fn_name(addr, deadline, request);
rpc.callback = Some(Box::new(CB(self.clone(), cb, PhantomData::<$response_type>)));
self.send_to_leader(rpc);
}
};
}
#[derive(Clone)]
pub struct MasterProxy {
inner: Arc<Mutex<Inner>>,
messenger: Messenger,
}
struct Inner {
leader: Leader,
replicas: HashSet<SocketAddr>,
}
impl MasterProxy {
pub fn new(replicas: &[SocketAddr], messenger: Messenger) -> MasterProxy {
assert!(replicas.len() > 0);
let replicas = replicas.iter().cloned().collect();
let proxy = MasterProxy {
inner: Arc::new(Mutex::new(Inner {
leader: Leader::Unknown(QueueMap::with_capacity(QUEUE_LEN)),
replicas: replicas,
})),
messenger: messenger,
};
proxy.refresh_leader_cache();
proxy
}
pub fn messenger(&self) -> &Messenger {
&self.messenger
}
pub fn masters(&self) -> Vec<SocketAddr> {
let mut masters = Vec::with_capacity(5);
masters.extend(self.inner.lock().replicas.iter().cloned());
masters
}
pub fn leader(&self) -> Option<SocketAddr> {
match self.inner.lock().leader {
Leader::Known(leader) => Some(leader),
Leader::Unknown(_) => None,
}
}
impl_master_rpc!(alter_table, AlterTableRequestPB, AlterTableResponsePB);
impl_master_rpc!(create_table, CreateTableRequestPB, CreateTableResponsePB);
impl_master_rpc!(delete_table, DeleteTableRequestPB, DeleteTableResponsePB);
impl_master_rpc!(get_table_locations, GetTableLocationsRequestPB, GetTableLocationsResponsePB);
impl_master_rpc!(get_table_schema, GetTableSchemaRequestPB, GetTableSchemaResponsePB);
impl_master_rpc!(get_tablet_locations, GetTabletLocationsRequestPB, GetTabletLocationsResponsePB);
impl_master_rpc!(is_alter_table_done, IsAlterTableDoneRequestPB, IsAlterTableDoneResponsePB);
impl_master_rpc!(is_create_table_done, IsCreateTableDoneRequestPB, IsCreateTableDoneResponsePB);
impl_master_rpc!(list_masters, ListMastersRequestPB, ListMastersResponsePB);
impl_master_rpc!(list_tables, ListTablesRequestPB, ListTablesResponsePB);
impl_master_rpc!(list_tablet_servers, ListTabletServersRequestPB, ListTabletServersResponsePB);
impl_master_rpc!(ping, PingRequestPB, PingResponsePB);
pub fn send_to_leader(&self, rpc: Rpc) {
fn inner(master_proxy: &MasterProxy, mut rpc: Rpc) -> Option<usize> {
let leader_addr = {
let mut inner = master_proxy.inner.lock();
match inner.leader {
Leader::Known(addr) => Some(addr),
Leader::Unknown(ref mut queue) => {
if queue.len() < QUEUE_LEN {
return Some(queue.push(rpc));
}
None
},
}
};
if let Some(leader_addr) = leader_addr {
rpc.addr = leader_addr;
master_proxy.messenger.send(rpc);
} else {
rpc.fail(Error::Backoff);
}
None
}
let now = Instant::now();
if rpc.timed_out(now) {
rpc.fail(Error::TimedOut);
return;
}
let duration = rpc.deadline.duration_since(now);
if let Some(queue_idx) = inner(self, rpc) {
let master_proxy = self.clone();
self.messenger.timer(duration, Box::new(move || {
master_proxy.timeout_queued_rpc(queue_idx)
}));
}
}
fn timeout_queued_rpc(&self, queue_idx: usize) {
let mut rpc = None;
if let Leader::Unknown(ref mut queue) = self.inner.lock().leader {
rpc = queue.remove(queue_idx);
}
if let Some(rpc) = rpc {
if rpc.timed_out(Instant::now()) {
rpc.fail(Error::TimedOut);
} else {
self.send_to_leader(rpc);
}
}
}
fn reset_leader_cache(&self, stale_leader: SocketAddr) {
let queue = QueueMap::with_capacity(QUEUE_LEN);
{
let mut inner = self.inner.lock();
match inner.leader {
Leader::Unknown(_) => return,
Leader::Known(leader) if leader != stale_leader => return,
_ => (),
}
inner.leader = Leader::Unknown(queue);
}
self.refresh_leader_cache();
}
fn refresh_leader_cache(&self) {
debug_assert!(!self.inner.lock().leader.is_known());
let cancel = Arc::new(AtomicBool::new(false));
let replicas = self.inner.lock().replicas.iter().cloned().collect::<Vec<_>>();
debug!("refreshing leader master from known replicas: {:?}", replicas);
let deadline = Instant::now() + Duration::from_secs(LEADER_REFRESH_TIMEOUT_SECS);
for addr in replicas {
self.send_list_masters(addr, deadline, cancel.clone());
}
}
fn send_list_masters(&self, addr: SocketAddr, deadline: Instant, cancel: Arc<AtomicBool>) {
trace!("sending ListMasters RPC to {}", addr);
let backoff = Backoff::with_duration_range(10, 30_000);
let mut rpc = master::list_masters(addr, deadline, ListMastersRequestPB::new());
rpc.cancel = Some(cancel);
rpc.fail_fast = false;
let proxy = self.clone();
rpc.callback = Some(Box::new(move |result, rpc: Rpc| {
thread::spawn(move || proxy.handle_list_masters_response(result, rpc, backoff));
}));
self.messenger.send(rpc);
}
fn retry_list_masters(self, mut rpc: Rpc, mut backoff: Backoff) {
if rpc.cancelled() { return; }
let delay_ms = backoff.next_backoff_ms();
let delay = Duration::from_millis(delay_ms);
let proxy = self.clone();
rpc.callback = Some(Box::new(move |result, rpc: Rpc| {
thread::spawn(move || proxy.handle_list_masters_response(result, rpc, backoff));
}));
rpc.deadline = Instant::now() +
Duration::from_millis(delay_ms) +
Duration::from_secs(LEADER_REFRESH_TIMEOUT_SECS);
trace!("retrying ListMasters RPC to {} after delay of {}ms", rpc.addr, delay_ms);
self.messenger.delayed_send(delay, rpc);
}
fn handle_list_masters_response(self, result: Result<()>, mut rpc: Rpc, backoff: Backoff) {
if rpc.cancelled() { return; }
let addr = rpc.addr;
let mut replicas: HashSet<SocketAddr> = HashSet::new();
let mut leader: HashSet<SocketAddr> = HashSet::new();
if let Err(error) = result {
info!("ListMasters RPC to master {} failed: {}", addr, error);
} else {
let response = rpc.mut_response::<ListMastersResponsePB>();
if response.has_error() {
info!("ListMasters RPC to master {} failed: {:?}", addr, response.get_error());
} else {
debug!("ListMasters RPC to master {} response: {:?}", addr, response);
for server_entry in response.mut_masters().iter_mut() {
if server_entry.has_error() { continue; }
let addrs = dns::resolve_hosts(server_entry.get_registration()
.get_rpc_addresses());
replicas.extend(addrs.iter().cloned());
if server_entry.get_role() == Role::LEADER {
assert!(leader.is_empty());
leader = addrs;
}
}
}
}
if rpc.cancelled() { return; }
let cancel = rpc.cancel.as_ref().unwrap().clone();
if replicas.is_empty() {
self.retry_list_masters(rpc, backoff);
} else if leader.is_empty() {
self.handle_discovered_replicas(replicas, cancel);
self.retry_list_masters(rpc, backoff);
} else {
self.handle_discovered_leaders(leader, replicas, cancel);
}
}
fn handle_discovered_replicas(&self, addrs: HashSet<SocketAddr>, cancel: Arc<AtomicBool>) {
let mut discovered_replicas = Vec::with_capacity(addrs.len());
{
let mut inner = self.inner.lock();
if cancel.load(Ordering::Relaxed) { return; }
for addr in addrs {
if inner.replicas.insert(addr) { discovered_replicas.push(addr); }
}
}
if !discovered_replicas.is_empty() {
info!("discovered replicas: [{}]", discovered_replicas.iter().format(", "));
let deadline = Instant::now() + Duration::from_secs(LEADER_REFRESH_TIMEOUT_SECS);
for addr in discovered_replicas {
self.send_list_masters(addr, deadline, cancel.clone());
}
}
}
fn handle_discovered_leaders(&self,
leader: HashSet<SocketAddr>,
replicas: HashSet<SocketAddr>,
cancel: Arc<AtomicBool>) {
let addr = match leader.iter().next() {
Some(&addr) => addr,
None => return,
};
let inner = {
let mut inner = self.inner.lock();
if cancel.compare_and_swap(false, true, Ordering::Relaxed) {
return;
}
mem::replace(&mut *inner, Inner { leader: Leader::Known(addr), replicas: replicas })
};
if leader.len() > 1 {
info!("discovered leader master {}, chosen from resolved addresses [{}]",
addr, leader.iter().format(", "));
} else {
info!("discovered leader master {}", addr);
}
match inner.leader {
Leader::Unknown(mut queue) => {
while let Some((_, mut rpc)) = queue.pop() {
rpc.addr = addr;
self.messenger.send(rpc);
}
},
Leader::Known(prev_addr) => unreachable!("existing known leader {} swapped for {}",
prev_addr, &addr),
}
}
}
enum Leader {
Known(SocketAddr),
Unknown(QueueMap<Rpc>),
}
impl Leader {
fn is_known(&self) -> bool {
match *self {
Leader::Known(_) => true,
Leader::Unknown(_) => false,
}
}
}
trait MasterResponse: Message {
fn error(&mut self) -> Option<MasterError>;
}
macro_rules! impl_master_response {
($response_type:ident) => {
impl MasterResponse for $response_type {
fn error(&mut self) -> Option<MasterError> {
if self.has_error() { Some(MasterError::from(self.take_error())) } else { None }
}
}
};
($response_type:ident, no_error) => {
impl MasterResponse for $response_type {
fn error(&mut self) -> Option<MasterError> { None }
}
};
}
impl_master_response!(AlterTableResponsePB);
impl_master_response!(CreateTableResponsePB);
impl_master_response!(DeleteTableResponsePB);
impl_master_response!(GetTableLocationsResponsePB);
impl_master_response!(GetTableSchemaResponsePB);
impl_master_response!(GetTabletLocationsResponsePB);
impl_master_response!(IsAlterTableDoneResponsePB);
impl_master_response!(IsCreateTableDoneResponsePB);
impl_master_response!(ListTablesResponsePB);
impl_master_response!(ListTabletServersResponsePB);
impl_master_response!(PingResponsePB, no_error);
impl MasterResponse for ListMastersResponsePB {
fn error(&mut self) -> Option<MasterError> {
if self.has_error() {
Some(MasterError::new(MasterErrorCode::UnknownError, Status::from(self.take_error())))
} else { None }
}
}
struct CB<Resp, F>(MasterProxy, F, PhantomData<Resp>)
where Resp: MasterResponse, F: FnOnce(Result<Resp>) + Send + 'static;
impl <Resp, F> Callback for CB<Resp, F>
where Resp: MasterResponse, F: FnOnce(Result<Resp>) + Send + 'static {
fn callback(self: Box<Self>, result: Result<()>, mut rpc: Rpc) {
match result {
Ok(_) => match rpc.mut_response::<Resp>().error() {
Some(ref error) if error.code() == MasterErrorCode::NotTheLeader ||
error.code() == MasterErrorCode::CatalogManagerNotInitialized => {
self.0.reset_leader_cache(rpc.addr);
let proxy: MasterProxy = self.0.clone();
rpc.callback = Some(self);
proxy.send_to_leader(rpc);
},
Some(error) => self.1(Err(Error::from(MasterError::from(error)))),
None => self.1(Ok(rpc.take_response::<Resp>())),
},
Err(ref error) if error.is_network_error() => {
self.0.reset_leader_cache(rpc.addr);
let proxy: MasterProxy = self.0.clone();
rpc.callback = Some(self);
proxy.send_to_leader(rpc);
}
Err(error) => self.1(Err(error)),
}
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Master {
id: MasterId,
rpc_addrs: Vec<(String, u16)>,
http_addrs: Vec<(String, u16)>,
seqno: i64,
role: RaftRole,
}
impl Master {
pub fn id(&self) -> &MasterId {
&self.id
}
pub fn rpc_addrs(&self) -> &[(String, u16)] {
&self.rpc_addrs
}
pub fn http_addrs(&self) -> &[(String, u16)] {
&self.http_addrs
}
pub fn seqno(&self) -> i64 {
self.seqno
}
pub fn role(&self) -> RaftRole {
self.role
}
#[doc(hidden)]
pub fn from_pb(mut master: MasterEntry) -> Result<Master> {
if master.has_error() {
return Err(Error::from(MasterError::new(MasterErrorCode::UnknownError,
Status::from(master.take_error()))))
}
let id = try!(MasterId::parse_bytes(master.get_instance_id().get_permanent_uuid()));
let seqno = master.get_instance_id().get_instance_seqno();
let rpc_addrs = master.mut_registration()
.take_rpc_addresses()
.into_iter()
.map(|mut host_port| (host_port.take_host(),
host_port.get_port() as u16))
.collect::<Vec<_>>();
let http_addrs = master.mut_registration()
.take_http_addresses()
.into_iter()
.map(|mut host_port| (host_port.take_host(),
host_port.get_port() as u16))
.collect::<Vec<_>>();
let role = RaftRole::from_pb(master.get_role());
Ok(Master {
id: id,
rpc_addrs: rpc_addrs,
http_addrs: http_addrs,
seqno: seqno,
role: role,
})
}
}
#[cfg(test)]
mod tests {
use std::collections::HashSet;
use std::time::{Duration, Instant};
use std::sync::mpsc::sync_channel;
use mini_cluster::{MiniCluster, MiniClusterConfig};
use rpc:: Messenger;
use Error;
use Result;
use super::*;
use env_logger;
use kudu_pb::master::{ListTablesRequestPB, ListTablesResponsePB};
fn check_list_tables_response(result: Result<ListTablesResponsePB>) {
let response = result.unwrap();
assert!(!response.has_error(), "failed response: {:?}", response);
assert!(response.get_tables().is_empty(), "response: {:?}", response);
}
#[test]
fn leader_discovery_single_master() {
let _ = env_logger::init();
let cluster = MiniCluster::new(MiniClusterConfig::default().num_tservers(0));
let proxy = MasterProxy::new(cluster.master_addrs(), Messenger::new().unwrap());
let (send, recv) = sync_channel(0);
proxy.list_tables(Instant::now() + Duration::from_secs(5),
ListTablesRequestPB::new(), move |resp| send.send(resp).unwrap());
let result = recv.recv().unwrap();
check_list_tables_response(result);
}
#[test]
fn leader_discovery_multi_master() {
let _ = env_logger::init();
let cluster = MiniCluster::new(MiniClusterConfig::default().num_masters(3).num_tservers(0));
let proxy = MasterProxy::new(cluster.master_addrs(), Messenger::new().unwrap());
let (send, recv) = sync_channel(0);
proxy.list_tables(Instant::now() + Duration::from_secs(5),
ListTablesRequestPB::new(), move |resp| send.send(resp).unwrap());
let result = recv.recv().unwrap();
check_list_tables_response(result);
}
#[test]
fn master_discovery() {
let _ = env_logger::init();
let cluster = MiniCluster::new(MiniClusterConfig::default().num_masters(2).num_tservers(0));
let proxy = MasterProxy::new(&cluster.master_addrs()[0..1], Messenger::new().unwrap());
let (send, recv) = sync_channel(0);
proxy.list_tables(Instant::now() + Duration::from_secs(5),
ListTablesRequestPB::new(), move |resp| send.send(resp).unwrap());
let result = recv.recv().unwrap();
check_list_tables_response(result);
let mut discovered_masters = HashSet::new();
let mut cluster_masters = HashSet::new();
discovered_masters.extend(proxy.masters());
cluster_masters.extend(cluster.master_addrs().iter().cloned());
assert_eq!(cluster_masters, discovered_masters);
}
fn master_cleanup() {
}
#[test]
fn timeout() {
let _ = env_logger::init();
let mut cluster = MiniCluster::new(MiniClusterConfig::default()
.num_masters(2)
.num_tservers(0)
.log_rpc_negotiation_trace(true)
.rpc_negotiation_delay(1000));
let addr = cluster.master_addrs()[0];
cluster.stop_node(addr);
let proxy = MasterProxy::new(cluster.master_addrs(), Messenger::new().unwrap());
let now = Instant::now();
let (send, recv) = sync_channel(0);
proxy.list_tables(now + Duration::from_millis(100),
ListTablesRequestPB::new(), move |resp| send.send(resp).unwrap());
let result = recv.recv().unwrap();
let elapsed = Instant::now().duration_since(now);
assert_eq!(Err(Error::TimedOut), result);
assert!(elapsed > Duration::from_millis(100), "expected: 100ms, elapsed: {:?}", elapsed);
assert!(elapsed < Duration::from_millis(150), "expected: 100ms, elapsed: {:?}", elapsed);
}
#[test]
fn leader_failover() {
let _ = env_logger::init();
let mut cluster = MiniCluster::new(MiniClusterConfig::default()
.num_masters(3)
.num_tservers(0));
let proxy = MasterProxy::new(&cluster.master_addrs()[0..1], Messenger::new().unwrap());
let (send, recv) = sync_channel(1);
let send_copy = send.clone();
proxy.list_tables(Instant::now() + Duration::from_secs(5),
ListTablesRequestPB::new(), move |resp| send_copy.send(resp).unwrap());
let result = recv.recv().unwrap();
check_list_tables_response(result);
assert_eq!(3, proxy.masters().len());
info!("Stopping leader {}", proxy.leader().unwrap());
cluster.stop_node(proxy.leader().unwrap());
proxy.list_tables(Instant::now() + Duration::from_secs(10),
ListTablesRequestPB::new(), move |resp| {
send.send(resp).unwrap()
});
let result = recv.recv().unwrap();
check_list_tables_response(result);
}
}