Line data Source code
1 : //! This module contains global `(tenant_id, timeline_id)` -> `Arc<Timeline>` mapping.
2 : //! All timelines should always be present in this map, this is done by loading them
3 : //! all from the disk on startup and keeping them in memory.
4 :
5 : use crate::safekeeper::ServerInfo;
6 : use crate::timeline::{get_tenant_dir, get_timeline_dir, Timeline, TimelineError};
7 : use crate::timelines_set::TimelinesSet;
8 : use crate::wal_backup_partial::RateLimiter;
9 : use crate::SafeKeeperConf;
10 : use anyhow::{bail, Context, Result};
11 : use camino::Utf8PathBuf;
12 : use once_cell::sync::Lazy;
13 : use serde::Serialize;
14 : use std::collections::HashMap;
15 : use std::str::FromStr;
16 : use std::sync::atomic::Ordering;
17 : use std::sync::{Arc, Mutex};
18 : use tracing::*;
19 : use utils::id::{TenantId, TenantTimelineId, TimelineId};
20 : use utils::lsn::Lsn;
21 :
22 : struct GlobalTimelinesState {
23 : timelines: HashMap<TenantTimelineId, Arc<Timeline>>,
24 : conf: Option<SafeKeeperConf>,
25 : broker_active_set: Arc<TimelinesSet>,
26 : load_lock: Arc<tokio::sync::Mutex<TimelineLoadLock>>,
27 : partial_backup_rate_limiter: RateLimiter,
28 : }
29 :
30 : // Used to prevent concurrent timeline loading.
31 : pub struct TimelineLoadLock;
32 :
33 : impl GlobalTimelinesState {
34 : /// Get configuration, which must be set once during init.
35 0 : fn get_conf(&self) -> &SafeKeeperConf {
36 0 : self.conf
37 0 : .as_ref()
38 0 : .expect("GlobalTimelinesState conf is not initialized")
39 0 : }
40 :
41 : /// Get dependencies for a timeline constructor.
42 0 : fn get_dependencies(&self) -> (SafeKeeperConf, Arc<TimelinesSet>, RateLimiter) {
43 0 : (
44 0 : self.get_conf().clone(),
45 0 : self.broker_active_set.clone(),
46 0 : self.partial_backup_rate_limiter.clone(),
47 0 : )
48 0 : }
49 :
50 : /// Insert timeline into the map. Returns error if timeline with the same id already exists.
51 0 : fn try_insert(&mut self, timeline: Arc<Timeline>) -> Result<()> {
52 0 : let ttid = timeline.ttid;
53 0 : if self.timelines.contains_key(&ttid) {
54 0 : bail!(TimelineError::AlreadyExists(ttid));
55 0 : }
56 0 : self.timelines.insert(ttid, timeline);
57 0 : Ok(())
58 0 : }
59 :
60 : /// Get timeline from the map. Returns error if timeline doesn't exist.
61 0 : fn get(&self, ttid: &TenantTimelineId) -> Result<Arc<Timeline>, TimelineError> {
62 0 : self.timelines
63 0 : .get(ttid)
64 0 : .cloned()
65 0 : .ok_or(TimelineError::NotFound(*ttid))
66 0 : }
67 : }
68 :
69 0 : static TIMELINES_STATE: Lazy<Mutex<GlobalTimelinesState>> = Lazy::new(|| {
70 0 : Mutex::new(GlobalTimelinesState {
71 0 : timelines: HashMap::new(),
72 0 : conf: None,
73 0 : broker_active_set: Arc::new(TimelinesSet::default()),
74 0 : load_lock: Arc::new(tokio::sync::Mutex::new(TimelineLoadLock)),
75 0 : partial_backup_rate_limiter: RateLimiter::new(1),
76 0 : })
77 0 : });
78 :
79 : /// A zero-sized struct used to manage access to the global timelines map.
80 : pub struct GlobalTimelines;
81 :
82 : impl GlobalTimelines {
83 : /// Inject dependencies needed for the timeline constructors and load all timelines to memory.
84 0 : pub async fn init(conf: SafeKeeperConf) -> Result<()> {
85 0 : // clippy isn't smart enough to understand that drop(state) releases the
86 0 : // lock, so use explicit block
87 0 : let tenants_dir = {
88 0 : let mut state = TIMELINES_STATE.lock().unwrap();
89 0 : state.partial_backup_rate_limiter = RateLimiter::new(conf.partial_backup_concurrency);
90 0 : state.conf = Some(conf);
91 0 :
92 0 : // Iterate through all directories and load tenants for all directories
93 0 : // named as a valid tenant_id.
94 0 : state.get_conf().workdir.clone()
95 0 : };
96 0 : let mut tenant_count = 0;
97 0 : for tenants_dir_entry in std::fs::read_dir(&tenants_dir)
98 0 : .with_context(|| format!("failed to list tenants dir {}", tenants_dir))?
99 : {
100 0 : match &tenants_dir_entry {
101 0 : Ok(tenants_dir_entry) => {
102 0 : if let Ok(tenant_id) =
103 0 : TenantId::from_str(tenants_dir_entry.file_name().to_str().unwrap_or(""))
104 : {
105 0 : tenant_count += 1;
106 0 : GlobalTimelines::load_tenant_timelines(tenant_id).await?;
107 0 : }
108 : }
109 0 : Err(e) => error!(
110 0 : "failed to list tenants dir entry {:?} in directory {}, reason: {:?}",
111 : tenants_dir_entry, tenants_dir, e
112 : ),
113 : }
114 : }
115 :
116 0 : info!(
117 0 : "found {} tenants directories, successfully loaded {} timelines",
118 0 : tenant_count,
119 0 : TIMELINES_STATE.lock().unwrap().timelines.len()
120 : );
121 0 : Ok(())
122 0 : }
123 :
124 : /// Loads all timelines for the given tenant to memory. Returns fs::read_dir
125 : /// errors if any.
126 : ///
127 : /// It is async for update_status_notify sake. Since TIMELINES_STATE lock is
128 : /// sync and there is no important reason to make it async (it is always
129 : /// held for a short while) we just lock and unlock it for each timeline --
130 : /// this function is called during init when nothing else is running, so
131 : /// this is fine.
132 0 : async fn load_tenant_timelines(tenant_id: TenantId) -> Result<()> {
133 0 : let (conf, broker_active_set, partial_backup_rate_limiter) = {
134 0 : let state = TIMELINES_STATE.lock().unwrap();
135 0 : state.get_dependencies()
136 0 : };
137 0 :
138 0 : let timelines_dir = get_tenant_dir(&conf, &tenant_id);
139 0 : for timelines_dir_entry in std::fs::read_dir(&timelines_dir)
140 0 : .with_context(|| format!("failed to list timelines dir {}", timelines_dir))?
141 : {
142 0 : match &timelines_dir_entry {
143 0 : Ok(timeline_dir_entry) => {
144 0 : if let Ok(timeline_id) =
145 0 : TimelineId::from_str(timeline_dir_entry.file_name().to_str().unwrap_or(""))
146 : {
147 0 : let ttid = TenantTimelineId::new(tenant_id, timeline_id);
148 0 : match Timeline::load_timeline(&conf, ttid) {
149 0 : Ok(timeline) => {
150 0 : let tli = Arc::new(timeline);
151 0 : TIMELINES_STATE
152 0 : .lock()
153 0 : .unwrap()
154 0 : .timelines
155 0 : .insert(ttid, tli.clone());
156 0 : tli.bootstrap(
157 0 : &conf,
158 0 : broker_active_set.clone(),
159 0 : partial_backup_rate_limiter.clone(),
160 0 : );
161 0 : }
162 : // If we can't load a timeline, it's most likely because of a corrupted
163 : // directory. We will log an error and won't allow to delete/recreate
164 : // this timeline. The only way to fix this timeline is to repair manually
165 : // and restart the safekeeper.
166 0 : Err(e) => error!(
167 0 : "failed to load timeline {} for tenant {}, reason: {:?}",
168 : timeline_id, tenant_id, e
169 : ),
170 : }
171 0 : }
172 : }
173 0 : Err(e) => error!(
174 0 : "failed to list timelines dir entry {:?} in directory {}, reason: {:?}",
175 : timelines_dir_entry, timelines_dir, e
176 : ),
177 : }
178 : }
179 :
180 0 : Ok(())
181 0 : }
182 :
183 : /// Take a lock for timeline loading.
184 0 : pub async fn loading_lock() -> Arc<tokio::sync::Mutex<TimelineLoadLock>> {
185 0 : TIMELINES_STATE.lock().unwrap().load_lock.clone()
186 0 : }
187 :
188 : /// Load timeline from disk to the memory.
189 0 : pub async fn load_timeline<'a>(
190 0 : _guard: &tokio::sync::MutexGuard<'a, TimelineLoadLock>,
191 0 : ttid: TenantTimelineId,
192 0 : ) -> Result<Arc<Timeline>> {
193 0 : let (conf, broker_active_set, partial_backup_rate_limiter) =
194 0 : TIMELINES_STATE.lock().unwrap().get_dependencies();
195 0 :
196 0 : match Timeline::load_timeline(&conf, ttid) {
197 0 : Ok(timeline) => {
198 0 : let tli = Arc::new(timeline);
199 0 :
200 0 : // TODO: prevent concurrent timeline creation/loading
201 0 : TIMELINES_STATE
202 0 : .lock()
203 0 : .unwrap()
204 0 : .timelines
205 0 : .insert(ttid, tli.clone());
206 0 :
207 0 : tli.bootstrap(&conf, broker_active_set, partial_backup_rate_limiter);
208 0 :
209 0 : Ok(tli)
210 : }
211 : // If we can't load a timeline, it's bad. Caller will figure it out.
212 0 : Err(e) => bail!("failed to load timeline {}, reason: {:?}", ttid, e),
213 : }
214 0 : }
215 :
216 : /// Get the number of timelines in the map.
217 0 : pub fn timelines_count() -> usize {
218 0 : TIMELINES_STATE.lock().unwrap().timelines.len()
219 0 : }
220 :
221 : /// Get the global safekeeper config.
222 0 : pub fn get_global_config() -> SafeKeeperConf {
223 0 : TIMELINES_STATE.lock().unwrap().get_conf().clone()
224 0 : }
225 :
226 0 : pub fn get_global_broker_active_set() -> Arc<TimelinesSet> {
227 0 : TIMELINES_STATE.lock().unwrap().broker_active_set.clone()
228 0 : }
229 :
230 : /// Create a new timeline with the given id. If the timeline already exists, returns
231 : /// an existing timeline.
232 0 : pub async fn create(
233 0 : ttid: TenantTimelineId,
234 0 : server_info: ServerInfo,
235 0 : commit_lsn: Lsn,
236 0 : local_start_lsn: Lsn,
237 0 : ) -> Result<Arc<Timeline>> {
238 0 : let (conf, broker_active_set, partial_backup_rate_limiter) = {
239 0 : let state = TIMELINES_STATE.lock().unwrap();
240 0 : if let Ok(timeline) = state.get(&ttid) {
241 : // Timeline already exists, return it.
242 0 : return Ok(timeline);
243 0 : }
244 0 : state.get_dependencies()
245 0 : };
246 0 :
247 0 : info!("creating new timeline {}", ttid);
248 :
249 0 : let timeline = Arc::new(Timeline::create_empty(
250 0 : &conf,
251 0 : ttid,
252 0 : server_info,
253 0 : commit_lsn,
254 0 : local_start_lsn,
255 0 : )?);
256 :
257 : // Take a lock and finish the initialization holding this mutex. No other threads
258 : // can interfere with creation after we will insert timeline into the map.
259 : {
260 0 : let mut shared_state = timeline.write_shared_state().await;
261 :
262 : // We can get a race condition here in case of concurrent create calls, but only
263 : // in theory. create() will return valid timeline on the next try.
264 0 : TIMELINES_STATE
265 0 : .lock()
266 0 : .unwrap()
267 0 : .try_insert(timeline.clone())?;
268 :
269 : // Write the new timeline to the disk and start background workers.
270 : // Bootstrap is transactional, so if it fails, the timeline will be deleted,
271 : // and the state on disk should remain unchanged.
272 0 : if let Err(e) = timeline
273 0 : .init_new(
274 0 : &mut shared_state,
275 0 : &conf,
276 0 : broker_active_set,
277 0 : partial_backup_rate_limiter,
278 0 : )
279 0 : .await
280 : {
281 : // Note: the most likely reason for init failure is that the timeline
282 : // directory already exists on disk. This happens when timeline is corrupted
283 : // and wasn't loaded from disk on startup because of that. We want to preserve
284 : // the timeline directory in this case, for further inspection.
285 :
286 : // TODO: this is an unusual error, perhaps we should send it to sentry
287 : // TODO: compute will try to create timeline every second, we should add backoff
288 0 : error!("failed to init new timeline {}: {}", ttid, e);
289 :
290 : // Timeline failed to init, it cannot be used. Remove it from the map.
291 0 : TIMELINES_STATE.lock().unwrap().timelines.remove(&ttid);
292 0 : return Err(e);
293 0 : }
294 0 : // We are done with bootstrap, release the lock, return the timeline.
295 0 : // {} block forces release before .await
296 0 : }
297 0 : Ok(timeline)
298 0 : }
299 :
300 : /// Get a timeline from the global map. If it's not present, it doesn't exist on disk,
301 : /// or was corrupted and couldn't be loaded on startup. Returned timeline is always valid,
302 : /// i.e. loaded in memory and not cancelled.
303 0 : pub fn get(ttid: TenantTimelineId) -> Result<Arc<Timeline>, TimelineError> {
304 0 : let res = TIMELINES_STATE.lock().unwrap().get(&ttid);
305 0 :
306 0 : match res {
307 0 : Ok(tli) => {
308 0 : if tli.is_cancelled() {
309 0 : return Err(TimelineError::Cancelled(ttid));
310 0 : }
311 0 : Ok(tli)
312 : }
313 0 : _ => res,
314 : }
315 0 : }
316 :
317 : /// Returns all timelines. This is used for background timeline processes.
318 0 : pub fn get_all() -> Vec<Arc<Timeline>> {
319 0 : let global_lock = TIMELINES_STATE.lock().unwrap();
320 0 : global_lock
321 0 : .timelines
322 0 : .values()
323 0 : .filter(|t| !t.is_cancelled())
324 0 : .cloned()
325 0 : .collect()
326 0 : }
327 :
328 : /// Returns all timelines belonging to a given tenant. Used for deleting all timelines of a tenant,
329 : /// and that's why it can return cancelled timelines, to retry deleting them.
330 0 : fn get_all_for_tenant(tenant_id: TenantId) -> Vec<Arc<Timeline>> {
331 0 : let global_lock = TIMELINES_STATE.lock().unwrap();
332 0 : global_lock
333 0 : .timelines
334 0 : .values()
335 0 : .filter(|t| t.ttid.tenant_id == tenant_id)
336 0 : .cloned()
337 0 : .collect()
338 0 : }
339 :
340 : /// Cancels timeline, then deletes the corresponding data directory.
341 : /// If only_local, doesn't remove WAL segments in remote storage.
342 0 : pub async fn delete(
343 0 : ttid: &TenantTimelineId,
344 0 : only_local: bool,
345 0 : ) -> Result<TimelineDeleteForceResult> {
346 0 : let tli_res = TIMELINES_STATE.lock().unwrap().get(ttid);
347 0 : match tli_res {
348 0 : Ok(timeline) => {
349 0 : let was_active = timeline.broker_active.load(Ordering::Relaxed);
350 :
351 : // Take a lock and finish the deletion holding this mutex.
352 0 : let mut shared_state = timeline.write_shared_state().await;
353 :
354 0 : info!("deleting timeline {}, only_local={}", ttid, only_local);
355 0 : let dir_existed = timeline.delete(&mut shared_state, only_local).await?;
356 :
357 : // Remove timeline from the map.
358 : // FIXME: re-enable it once we fix the issue with recreation of deleted timelines
359 : // https://github.com/neondatabase/neon/issues/3146
360 : // TIMELINES_STATE.lock().unwrap().timelines.remove(ttid);
361 :
362 0 : Ok(TimelineDeleteForceResult {
363 0 : dir_existed,
364 0 : was_active, // TODO: we probably should remove this field
365 0 : })
366 : }
367 : Err(_) => {
368 : // Timeline is not memory, but it may still exist on disk in broken state.
369 0 : let dir_path = get_timeline_dir(TIMELINES_STATE.lock().unwrap().get_conf(), ttid);
370 0 : let dir_existed = delete_dir(dir_path)?;
371 :
372 0 : Ok(TimelineDeleteForceResult {
373 0 : dir_existed,
374 0 : was_active: false,
375 0 : })
376 : }
377 : }
378 0 : }
379 :
380 : /// Deactivates and deletes all timelines for the tenant. Returns map of all timelines which
381 : /// the tenant had, `true` if a timeline was active. There may be a race if new timelines are
382 : /// created simultaneously. In that case the function will return error and the caller should
383 : /// retry tenant deletion again later.
384 : ///
385 : /// If only_local, doesn't remove WAL segments in remote storage.
386 0 : pub async fn delete_force_all_for_tenant(
387 0 : tenant_id: &TenantId,
388 0 : only_local: bool,
389 0 : ) -> Result<HashMap<TenantTimelineId, TimelineDeleteForceResult>> {
390 0 : info!("deleting all timelines for tenant {}", tenant_id);
391 0 : let to_delete = Self::get_all_for_tenant(*tenant_id);
392 0 :
393 0 : let mut err = None;
394 0 :
395 0 : let mut deleted = HashMap::new();
396 0 : for tli in &to_delete {
397 0 : match Self::delete(&tli.ttid, only_local).await {
398 0 : Ok(result) => {
399 0 : deleted.insert(tli.ttid, result);
400 0 : }
401 0 : Err(e) => {
402 0 : error!("failed to delete timeline {}: {}", tli.ttid, e);
403 : // Save error to return later.
404 0 : err = Some(e);
405 : }
406 : }
407 : }
408 :
409 : // If there was an error, return it.
410 0 : if let Some(e) = err {
411 0 : return Err(e);
412 0 : }
413 0 :
414 0 : // There may be broken timelines on disk, so delete the whole tenant dir as well.
415 0 : // Note that we could concurrently create new timelines while we were deleting them,
416 0 : // so the directory may be not empty. In this case timelines will have bad state
417 0 : // and timeline background jobs can panic.
418 0 : delete_dir(get_tenant_dir(
419 0 : TIMELINES_STATE.lock().unwrap().get_conf(),
420 0 : tenant_id,
421 0 : ))?;
422 :
423 : // FIXME: we temporarily disabled removing timelines from the map, see `delete_force`
424 : // let tlis_after_delete = Self::get_all_for_tenant(*tenant_id);
425 : // if !tlis_after_delete.is_empty() {
426 : // // Some timelines were created while we were deleting them, returning error
427 : // // to the caller, so it can retry later.
428 : // bail!(
429 : // "failed to delete all timelines for tenant {}: some timelines were created while we were deleting them",
430 : // tenant_id
431 : // );
432 : // }
433 :
434 0 : Ok(deleted)
435 0 : }
436 : }
437 :
438 : #[derive(Clone, Copy, Serialize)]
439 : pub struct TimelineDeleteForceResult {
440 : pub dir_existed: bool,
441 : pub was_active: bool,
442 : }
443 :
444 : /// Deletes directory and it's contents. Returns false if directory does not exist.
445 0 : fn delete_dir(path: Utf8PathBuf) -> Result<bool> {
446 0 : match std::fs::remove_dir_all(path) {
447 0 : Ok(_) => Ok(true),
448 0 : Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(false),
449 0 : Err(e) => Err(e.into()),
450 : }
451 0 : }
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