forked from Deuxfleurs/garage
Safety: never voluntarily delete block in 10min interval after RC reaches zero
This commit is contained in:
parent
cc255d46cd
commit
74a7a550eb
3 changed files with 182 additions and 51 deletions
|
@ -446,7 +446,7 @@ impl AdminRpcHandler {
|
||||||
if opt.detailed {
|
if opt.detailed {
|
||||||
writeln!(
|
writeln!(
|
||||||
&mut ret,
|
&mut ret,
|
||||||
" number of blocks: {}",
|
" number of RC entries (~= number of blocks): {}",
|
||||||
self.garage.block_manager.rc_len()
|
self.garage.block_manager.rc_len()
|
||||||
)
|
)
|
||||||
.unwrap();
|
.unwrap();
|
||||||
|
|
|
@ -8,8 +8,7 @@ pub enum Command {
|
||||||
#[structopt(name = "server")]
|
#[structopt(name = "server")]
|
||||||
Server,
|
Server,
|
||||||
|
|
||||||
/// Print identifier (public key) of this garage node.
|
/// Print identifier (public key) of this Garage node
|
||||||
/// Generates a new keypair if necessary.
|
|
||||||
#[structopt(name = "node-id")]
|
#[structopt(name = "node-id")]
|
||||||
NodeId(NodeIdOpt),
|
NodeId(NodeIdOpt),
|
||||||
|
|
||||||
|
|
|
@ -31,10 +31,20 @@ pub const INLINE_THRESHOLD: usize = 3072;
|
||||||
pub const BACKGROUND_WORKERS: u64 = 1;
|
pub const BACKGROUND_WORKERS: u64 = 1;
|
||||||
pub const BACKGROUND_TRANQUILITY: u32 = 3;
|
pub const BACKGROUND_TRANQUILITY: u32 = 3;
|
||||||
|
|
||||||
const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(42);
|
// Timeout for RPCs that read and write blocks to remote nodes
|
||||||
const BLOCK_GC_TIMEOUT: Duration = Duration::from_secs(60);
|
const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(30);
|
||||||
|
// Timeout for RPCs that ask other nodes whether they need a copy
|
||||||
|
// of a given block before we delete it locally
|
||||||
const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
|
const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
|
||||||
const RESYNC_RETRY_TIMEOUT: Duration = Duration::from_secs(10);
|
|
||||||
|
// The delay between the time where a resync operation fails
|
||||||
|
// and the time when it is retried.
|
||||||
|
const RESYNC_RETRY_DELAY: Duration = Duration::from_secs(60);
|
||||||
|
|
||||||
|
// The delay between the moment when the reference counter
|
||||||
|
// drops to zero, and the moment where we allow ourselves
|
||||||
|
// to delete the block locally.
|
||||||
|
const BLOCK_GC_DELAY: Duration = Duration::from_secs(600);
|
||||||
|
|
||||||
/// RPC messages used to share blocks of data between nodes
|
/// RPC messages used to share blocks of data between nodes
|
||||||
#[derive(Debug, Serialize, Deserialize)]
|
#[derive(Debug, Serialize, Deserialize)]
|
||||||
|
@ -180,7 +190,7 @@ impl BlockManager {
|
||||||
/// that are required because of refcount > 0, and will try
|
/// that are required because of refcount > 0, and will try
|
||||||
/// to fix any mismatch between the two.
|
/// to fix any mismatch between the two.
|
||||||
pub async fn repair_data_store(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
|
pub async fn repair_data_store(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
|
||||||
// 1. Repair blocks from RC table
|
// 1. Repair blocks from RC table.
|
||||||
let garage = self.garage.load_full().unwrap();
|
let garage = self.garage.load_full().unwrap();
|
||||||
let mut last_hash = None;
|
let mut last_hash = None;
|
||||||
for (i, entry) in garage.block_ref_table.data.store.iter().enumerate() {
|
for (i, entry) in garage.block_ref_table.data.store.iter().enumerate() {
|
||||||
|
@ -245,40 +255,51 @@ impl BlockManager {
|
||||||
/// Increment the number of time a block is used, putting it to resynchronization if it is
|
/// Increment the number of time a block is used, putting it to resynchronization if it is
|
||||||
/// required, but not known
|
/// required, but not known
|
||||||
pub fn block_incref(&self, hash: &Hash) -> Result<(), Error> {
|
pub fn block_incref(&self, hash: &Hash) -> Result<(), Error> {
|
||||||
let old_rc = self.rc.fetch_and_update(&hash, |old| {
|
let old_rc = self
|
||||||
let old_v = old.map(u64_from_be_bytes).unwrap_or(0);
|
.rc
|
||||||
Some(u64::to_be_bytes(old_v + 1).to_vec())
|
.fetch_and_update(&hash, |old| RcEntry::parse_opt(old).increment().serialize())?;
|
||||||
})?;
|
let old_rc = RcEntry::parse_opt(old_rc);
|
||||||
let old_rc = old_rc.map(u64_from_be_bytes).unwrap_or(0);
|
if old_rc.is_zero() {
|
||||||
if old_rc == 0 {
|
// When the reference counter is incremented, there is
|
||||||
self.put_to_resync(hash, BLOCK_RW_TIMEOUT)?;
|
// normally a node that is responsible for sending us the
|
||||||
|
// data of the block. However that operation may fail,
|
||||||
|
// so in all cases we add the block here to the todo list
|
||||||
|
// to check later that it arrived correctly, and if not
|
||||||
|
// we will fecth it from someone.
|
||||||
|
self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?;
|
||||||
}
|
}
|
||||||
Ok(())
|
Ok(())
|
||||||
}
|
}
|
||||||
|
|
||||||
/// Decrement the number of time a block is used
|
/// Decrement the number of time a block is used
|
||||||
pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> {
|
pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> {
|
||||||
let new_rc = self.rc.update_and_fetch(&hash, |old| {
|
let new_rc = self
|
||||||
let old_v = old.map(u64_from_be_bytes).unwrap_or(0);
|
.rc
|
||||||
if old_v > 1 {
|
.update_and_fetch(&hash, |old| RcEntry::parse_opt(old).decrement().serialize())?;
|
||||||
Some(u64::to_be_bytes(old_v - 1).to_vec())
|
let new_rc = RcEntry::parse_opt(new_rc);
|
||||||
} else {
|
if let RcEntry::Deletable { .. } = new_rc {
|
||||||
None
|
self.put_to_resync(hash, BLOCK_GC_DELAY + Duration::from_secs(10))?;
|
||||||
}
|
|
||||||
})?;
|
|
||||||
if new_rc.is_none() {
|
|
||||||
self.put_to_resync(hash, BLOCK_GC_TIMEOUT)?;
|
|
||||||
}
|
}
|
||||||
Ok(())
|
Ok(())
|
||||||
}
|
}
|
||||||
|
|
||||||
/// Read a block's reference count
|
/// Read a block's reference count
|
||||||
pub fn get_block_rc(&self, hash: &Hash) -> Result<u64, Error> {
|
fn get_block_rc(&self, hash: &Hash) -> Result<RcEntry, Error> {
|
||||||
Ok(self
|
Ok(RcEntry::parse_opt(self.rc.get(hash.as_ref())?))
|
||||||
.rc
|
}
|
||||||
.get(hash.as_ref())?
|
|
||||||
.map(u64_from_be_bytes)
|
/// Delete an entry in the RC table if it is deletable and the
|
||||||
.unwrap_or(0))
|
/// deletion time has passed
|
||||||
|
fn clear_deleted_block_rc(&self, hash: &Hash) -> Result<(), Error> {
|
||||||
|
let now = now_msec();
|
||||||
|
self.rc.update_and_fetch(&hash, |rcval| {
|
||||||
|
let updated = match RcEntry::parse_opt(rcval) {
|
||||||
|
RcEntry::Deletable { at_time } if now > at_time => RcEntry::Absent,
|
||||||
|
v => v,
|
||||||
|
};
|
||||||
|
updated.serialize()
|
||||||
|
})?;
|
||||||
|
Ok(())
|
||||||
}
|
}
|
||||||
|
|
||||||
// ---- Reading and writing blocks locally ----
|
// ---- Reading and writing blocks locally ----
|
||||||
|
@ -300,7 +321,7 @@ impl BlockManager {
|
||||||
Ok(f) => f,
|
Ok(f) => f,
|
||||||
Err(e) => {
|
Err(e) => {
|
||||||
// Not found but maybe we should have had it ??
|
// Not found but maybe we should have had it ??
|
||||||
self.put_to_resync(hash, Duration::from_millis(0))?;
|
self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?;
|
||||||
return Err(Into::into(e));
|
return Err(Into::into(e));
|
||||||
}
|
}
|
||||||
};
|
};
|
||||||
|
@ -314,6 +335,7 @@ impl BlockManager {
|
||||||
.await
|
.await
|
||||||
.move_block_to_corrupted(hash, self)
|
.move_block_to_corrupted(hash, self)
|
||||||
.await?;
|
.await?;
|
||||||
|
self.put_to_resync(hash, Duration::from_millis(0))?;
|
||||||
return Err(Error::CorruptData(*hash));
|
return Err(Error::CorruptData(*hash));
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -328,7 +350,7 @@ impl BlockManager {
|
||||||
.await
|
.await
|
||||||
.check_block_status(hash, self)
|
.check_block_status(hash, self)
|
||||||
.await?;
|
.await?;
|
||||||
Ok(needed && !exists)
|
Ok(needed.is_nonzero() && !exists)
|
||||||
}
|
}
|
||||||
|
|
||||||
/// Utility: gives the path of the directory in which a block should be found
|
/// Utility: gives the path of the directory in which a block should be found
|
||||||
|
@ -349,7 +371,7 @@ impl BlockManager {
|
||||||
// ---- Resync loop ----
|
// ---- Resync loop ----
|
||||||
|
|
||||||
pub fn spawn_background_worker(self: Arc<Self>) {
|
pub fn spawn_background_worker(self: Arc<Self>) {
|
||||||
// Launch 2 simultaneous workers for background resync loop preprocessing
|
// Launch n simultaneous workers for background resync loop preprocessing
|
||||||
for i in 0..BACKGROUND_WORKERS {
|
for i in 0..BACKGROUND_WORKERS {
|
||||||
let bm2 = self.clone();
|
let bm2 = self.clone();
|
||||||
let background = self.system.background.clone();
|
let background = self.system.background.clone();
|
||||||
|
@ -407,7 +429,7 @@ impl BlockManager {
|
||||||
let res = self.resync_block(&hash).await;
|
let res = self.resync_block(&hash).await;
|
||||||
if let Err(e) = &res {
|
if let Err(e) = &res {
|
||||||
warn!("Error when resyncing {:?}: {}", hash, e);
|
warn!("Error when resyncing {:?}: {}", hash, e);
|
||||||
self.put_to_resync(&hash, RESYNC_RETRY_TIMEOUT)?;
|
self.put_to_resync(&hash, RESYNC_RETRY_DELAY)?;
|
||||||
}
|
}
|
||||||
Ok(true)
|
Ok(true)
|
||||||
} else {
|
} else {
|
||||||
|
@ -437,15 +459,18 @@ impl BlockManager {
|
||||||
.check_block_status(hash, self)
|
.check_block_status(hash, self)
|
||||||
.await?;
|
.await?;
|
||||||
|
|
||||||
if exists != needed {
|
if exists != needed.is_needed() || exists != needed.is_nonzero() {
|
||||||
info!(
|
debug!(
|
||||||
"Resync block {:?}: exists {}, needed {}",
|
"Resync block {:?}: exists {}, nonzero rc {}, deletable {}",
|
||||||
hash, exists, needed
|
hash,
|
||||||
|
exists,
|
||||||
|
needed.is_nonzero(),
|
||||||
|
needed.is_deletable(),
|
||||||
);
|
);
|
||||||
}
|
}
|
||||||
|
|
||||||
if exists && !needed {
|
if exists && needed.is_deletable() {
|
||||||
trace!("Offloading block {:?}", hash);
|
info!("Resync block {:?}: offloading and deleting", hash);
|
||||||
|
|
||||||
let mut who = self.replication.write_nodes(hash);
|
let mut who = self.replication.write_nodes(hash);
|
||||||
if who.len() < self.replication.write_quorum() {
|
if who.len() < self.replication.write_quorum() {
|
||||||
|
@ -488,7 +513,7 @@ impl BlockManager {
|
||||||
need_nodes.len()
|
need_nodes.len()
|
||||||
);
|
);
|
||||||
|
|
||||||
let put_block_message = self.read_block(hash).await.err_context("PutBlock RPC")?;
|
let put_block_message = self.read_block(hash).await?;
|
||||||
self.system
|
self.system
|
||||||
.rpc
|
.rpc
|
||||||
.try_call_many(
|
.try_call_many(
|
||||||
|
@ -499,10 +524,11 @@ impl BlockManager {
|
||||||
.with_quorum(need_nodes.len())
|
.with_quorum(need_nodes.len())
|
||||||
.with_timeout(BLOCK_RW_TIMEOUT),
|
.with_timeout(BLOCK_RW_TIMEOUT),
|
||||||
)
|
)
|
||||||
.await?;
|
.await
|
||||||
|
.err_context("PutBlock RPC")?;
|
||||||
}
|
}
|
||||||
info!(
|
info!(
|
||||||
"Deleting block {:?}, offload finished ({} / {})",
|
"Deleting unneeded block {:?}, offload finished ({} / {})",
|
||||||
hash,
|
hash,
|
||||||
need_nodes.len(),
|
need_nodes.len(),
|
||||||
who.len()
|
who.len()
|
||||||
|
@ -513,12 +539,16 @@ impl BlockManager {
|
||||||
.await
|
.await
|
||||||
.delete_if_unneeded(hash, self)
|
.delete_if_unneeded(hash, self)
|
||||||
.await?;
|
.await?;
|
||||||
|
|
||||||
|
self.clear_deleted_block_rc(hash)?;
|
||||||
}
|
}
|
||||||
|
|
||||||
if needed && !exists {
|
if needed.is_nonzero() && !exists {
|
||||||
// TODO find a way to not do this if they are sending it to us
|
info!(
|
||||||
// Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay
|
"Resync block {:?}: fetching absent but needed block (refcount > 0)",
|
||||||
// between the RC being incremented and this part being called.
|
hash
|
||||||
|
);
|
||||||
|
|
||||||
let block_data = self.rpc_get_block(hash).await?;
|
let block_data = self.rpc_get_block(hash).await?;
|
||||||
self.write_block(hash, &block_data[..]).await?;
|
self.write_block(hash, &block_data[..]).await?;
|
||||||
}
|
}
|
||||||
|
@ -526,6 +556,8 @@ impl BlockManager {
|
||||||
Ok(())
|
Ok(())
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// ---- Utility: iteration on files in the data directory ----
|
||||||
|
|
||||||
async fn for_each_file<F, Fut, State>(
|
async fn for_each_file<F, Fut, State>(
|
||||||
&self,
|
&self,
|
||||||
state: State,
|
state: State,
|
||||||
|
@ -608,7 +640,7 @@ impl EndpointHandler<BlockRpc> for BlockManager {
|
||||||
|
|
||||||
struct BlockStatus {
|
struct BlockStatus {
|
||||||
exists: bool,
|
exists: bool,
|
||||||
needed: bool,
|
needed: RcEntry,
|
||||||
}
|
}
|
||||||
|
|
||||||
impl BlockManagerLocked {
|
impl BlockManagerLocked {
|
||||||
|
@ -620,7 +652,7 @@ impl BlockManagerLocked {
|
||||||
let path = mgr.block_path(hash);
|
let path = mgr.block_path(hash);
|
||||||
|
|
||||||
let exists = fs::metadata(&path).await.is_ok();
|
let exists = fs::metadata(&path).await.is_ok();
|
||||||
let needed = mgr.get_block_rc(hash)? > 0;
|
let needed = mgr.get_block_rc(hash)?;
|
||||||
|
|
||||||
Ok(BlockStatus { exists, needed })
|
Ok(BlockStatus { exists, needed })
|
||||||
}
|
}
|
||||||
|
@ -659,14 +691,13 @@ impl BlockManagerLocked {
|
||||||
let mut path2 = path.clone();
|
let mut path2 = path.clone();
|
||||||
path2.set_extension("corrupted");
|
path2.set_extension("corrupted");
|
||||||
fs::rename(path, path2).await?;
|
fs::rename(path, path2).await?;
|
||||||
mgr.put_to_resync(hash, Duration::from_millis(0))?;
|
|
||||||
Ok(())
|
Ok(())
|
||||||
}
|
}
|
||||||
|
|
||||||
async fn delete_if_unneeded(&self, hash: &Hash, mgr: &BlockManager) -> Result<(), Error> {
|
async fn delete_if_unneeded(&self, hash: &Hash, mgr: &BlockManager) -> Result<(), Error> {
|
||||||
let BlockStatus { exists, needed } = self.check_block_status(hash, mgr).await?;
|
let BlockStatus { exists, needed } = self.check_block_status(hash, mgr).await?;
|
||||||
|
|
||||||
if exists && !needed {
|
if exists && needed.is_deletable() {
|
||||||
let path = mgr.block_path(hash);
|
let path = mgr.block_path(hash);
|
||||||
fs::remove_file(path).await?;
|
fs::remove_file(path).await?;
|
||||||
}
|
}
|
||||||
|
@ -680,3 +711,104 @@ fn u64_from_be_bytes<T: AsRef<[u8]>>(bytes: T) -> u64 {
|
||||||
x8.copy_from_slice(bytes.as_ref());
|
x8.copy_from_slice(bytes.as_ref());
|
||||||
u64::from_be_bytes(x8)
|
u64::from_be_bytes(x8)
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/// Describes the state of the reference counter for a block
|
||||||
|
#[derive(Clone, Copy, Debug)]
|
||||||
|
enum RcEntry {
|
||||||
|
/// Present: the block has `count` references, with `count` > 0.
|
||||||
|
///
|
||||||
|
/// This is stored as u64::to_be_bytes(count)
|
||||||
|
Present { count: u64 },
|
||||||
|
|
||||||
|
/// Deletable: the block has zero references, and can be deleted
|
||||||
|
/// once time (returned by now_msec) is larger than at_time
|
||||||
|
/// (in millis since Unix epoch)
|
||||||
|
///
|
||||||
|
/// This is stored as [0u8; 8] followed by u64::to_be_bytes(at_time),
|
||||||
|
/// (this allows for the data format to be backwards compatible with
|
||||||
|
/// previous Garage versions that didn't have this intermediate state)
|
||||||
|
Deletable { at_time: u64 },
|
||||||
|
|
||||||
|
/// Absent: the block has zero references, and can be deleted
|
||||||
|
/// immediately
|
||||||
|
Absent,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl RcEntry {
|
||||||
|
fn parse(bytes: &[u8]) -> Self {
|
||||||
|
if bytes.len() == 8 {
|
||||||
|
RcEntry::Present {
|
||||||
|
count: u64::from_be_bytes(bytes.try_into().unwrap()),
|
||||||
|
}
|
||||||
|
} else if bytes.len() == 16 {
|
||||||
|
RcEntry::Deletable {
|
||||||
|
at_time: u64::from_be_bytes(bytes[8..16].try_into().unwrap()),
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
panic!("Invalid RC entry: {:?}, database is corrupted. This is an error Garage is currently unable to recover from. Sorry, and also please report a bug.",
|
||||||
|
bytes
|
||||||
|
)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn parse_opt<V: AsRef<[u8]>>(bytes: Option<V>) -> Self {
|
||||||
|
bytes
|
||||||
|
.map(|b| Self::parse(b.as_ref()))
|
||||||
|
.unwrap_or(Self::Absent)
|
||||||
|
}
|
||||||
|
|
||||||
|
fn serialize(self) -> Option<Vec<u8>> {
|
||||||
|
match self {
|
||||||
|
RcEntry::Present { count } => Some(u64::to_be_bytes(count).to_vec()),
|
||||||
|
RcEntry::Deletable { at_time } => {
|
||||||
|
Some([u64::to_be_bytes(0), u64::to_be_bytes(at_time)].concat())
|
||||||
|
}
|
||||||
|
RcEntry::Absent => None,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn increment(self) -> Self {
|
||||||
|
let old_count = match self {
|
||||||
|
RcEntry::Present { count } => count,
|
||||||
|
_ => 0,
|
||||||
|
};
|
||||||
|
RcEntry::Present {
|
||||||
|
count: old_count + 1,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn decrement(self) -> Self {
|
||||||
|
match self {
|
||||||
|
RcEntry::Present { count } => {
|
||||||
|
if count > 1 {
|
||||||
|
RcEntry::Present { count: count - 1 }
|
||||||
|
} else {
|
||||||
|
RcEntry::Deletable {
|
||||||
|
at_time: now_msec() + BLOCK_GC_DELAY.as_millis() as u64,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
del => del,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn is_zero(&self) -> bool {
|
||||||
|
matches!(self, RcEntry::Deletable { .. } | RcEntry::Absent)
|
||||||
|
}
|
||||||
|
|
||||||
|
fn is_nonzero(&self) -> bool {
|
||||||
|
!self.is_zero()
|
||||||
|
}
|
||||||
|
|
||||||
|
fn is_deletable(&self) -> bool {
|
||||||
|
match self {
|
||||||
|
RcEntry::Present { .. } => false,
|
||||||
|
RcEntry::Deletable { at_time } => now_msec() > *at_time,
|
||||||
|
RcEntry::Absent => true,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn is_needed(&self) -> bool {
|
||||||
|
!self.is_deletable()
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
Loading…
Reference in a new issue