TLA 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::{Timeline, TimelineError};
7 : use crate::SafeKeeperConf;
8 : use anyhow::{bail, Context, Result};
9 : use camino::Utf8PathBuf;
10 : use once_cell::sync::Lazy;
11 : use serde::Serialize;
12 : use std::collections::HashMap;
13 : use std::str::FromStr;
14 : use std::sync::{Arc, Mutex};
15 : use tokio::sync::mpsc::Sender;
16 : use tracing::*;
17 : use utils::id::{TenantId, TenantTimelineId, TimelineId};
18 : use utils::lsn::Lsn;
19 :
20 : struct GlobalTimelinesState {
21 : timelines: HashMap<TenantTimelineId, Arc<Timeline>>,
22 : wal_backup_launcher_tx: Option<Sender<TenantTimelineId>>,
23 : conf: Option<SafeKeeperConf>,
24 : load_lock: Arc<tokio::sync::Mutex<TimelineLoadLock>>,
25 : }
26 :
27 : // Used to prevent concurrent timeline loading.
28 : pub struct TimelineLoadLock;
29 :
30 : impl GlobalTimelinesState {
31 : /// Get configuration, which must be set once during init.
32 CBC 1188 : fn get_conf(&self) -> &SafeKeeperConf {
33 1188 : self.conf
34 1188 : .as_ref()
35 1188 : .expect("GlobalTimelinesState conf is not initialized")
36 1188 : }
37 :
38 : /// Get dependencies for a timeline constructor.
39 498 : fn get_dependencies(&self) -> (SafeKeeperConf, Sender<TenantTimelineId>) {
40 498 : (
41 498 : self.get_conf().clone(),
42 498 : self.wal_backup_launcher_tx.as_ref().unwrap().clone(),
43 498 : )
44 498 : }
45 :
46 : /// Insert timeline into the map. Returns error if timeline with the same id already exists.
47 449 : fn try_insert(&mut self, timeline: Arc<Timeline>) -> Result<()> {
48 449 : let ttid = timeline.ttid;
49 449 : if self.timelines.contains_key(&ttid) {
50 UBC 0 : bail!(TimelineError::AlreadyExists(ttid));
51 CBC 449 : }
52 449 : self.timelines.insert(ttid, timeline);
53 449 : Ok(())
54 449 : }
55 :
56 : /// Get timeline from the map. Returns error if timeline doesn't exist.
57 16447 : fn get(&self, ttid: &TenantTimelineId) -> Result<Arc<Timeline>, TimelineError> {
58 16447 : self.timelines
59 16447 : .get(ttid)
60 16447 : .cloned()
61 16447 : .ok_or(TimelineError::NotFound(*ttid))
62 16447 : }
63 : }
64 :
65 485 : static TIMELINES_STATE: Lazy<Mutex<GlobalTimelinesState>> = Lazy::new(|| {
66 485 : Mutex::new(GlobalTimelinesState {
67 485 : timelines: HashMap::new(),
68 485 : wal_backup_launcher_tx: None,
69 485 : conf: None,
70 485 : load_lock: Arc::new(tokio::sync::Mutex::new(TimelineLoadLock)),
71 485 : })
72 485 : });
73 :
74 : /// A zero-sized struct used to manage access to the global timelines map.
75 : pub struct GlobalTimelines;
76 :
77 : impl GlobalTimelines {
78 : /// Inject dependencies needed for the timeline constructors and load all timelines to memory.
79 485 : pub async fn init(
80 485 : conf: SafeKeeperConf,
81 485 : wal_backup_launcher_tx: Sender<TenantTimelineId>,
82 485 : ) -> Result<()> {
83 : // clippy isn't smart enough to understand that drop(state) releases the
84 : // lock, so use explicit block
85 485 : let tenants_dir = {
86 485 : let mut state = TIMELINES_STATE.lock().unwrap();
87 485 : assert!(state.wal_backup_launcher_tx.is_none());
88 485 : state.wal_backup_launcher_tx = Some(wal_backup_launcher_tx);
89 485 : state.conf = Some(conf);
90 485 :
91 485 : // Iterate through all directories and load tenants for all directories
92 485 : // named as a valid tenant_id.
93 485 : state.get_conf().workdir.clone()
94 485 : };
95 485 : let mut tenant_count = 0;
96 1537 : for tenants_dir_entry in std::fs::read_dir(&tenants_dir)
97 485 : .with_context(|| format!("failed to list tenants dir {}", tenants_dir))?
98 : {
99 1537 : match &tenants_dir_entry {
100 1537 : Ok(tenants_dir_entry) => {
101 81 : if let Ok(tenant_id) =
102 1537 : TenantId::from_str(tenants_dir_entry.file_name().to_str().unwrap_or(""))
103 : {
104 81 : tenant_count += 1;
105 81 : GlobalTimelines::load_tenant_timelines(tenant_id).await?;
106 1456 : }
107 : }
108 UBC 0 : Err(e) => error!(
109 0 : "failed to list tenants dir entry {:?} in directory {}, reason: {:?}",
110 0 : tenants_dir_entry, tenants_dir, e
111 0 : ),
112 : }
113 : }
114 :
115 CBC 485 : info!(
116 485 : "found {} tenants directories, successfully loaded {} timelines",
117 485 : tenant_count,
118 485 : TIMELINES_STATE.lock().unwrap().timelines.len()
119 485 : );
120 485 : Ok(())
121 485 : }
122 :
123 : /// Loads all timelines for the given tenant to memory. Returns fs::read_dir
124 : /// errors if any.
125 : ///
126 : /// It is async for update_status_notify sake. Since TIMELINES_STATE lock is
127 : /// sync and there is no important reason to make it async (it is always
128 : /// held for a short while) we just lock and unlock it for each timeline --
129 : /// this function is called during init when nothing else is running, so
130 : /// this is fine.
131 81 : async fn load_tenant_timelines(tenant_id: TenantId) -> Result<()> {
132 81 : let (conf, wal_backup_launcher_tx) = {
133 81 : let state = TIMELINES_STATE.lock().unwrap();
134 81 : (
135 81 : state.get_conf().clone(),
136 81 : state.wal_backup_launcher_tx.as_ref().unwrap().clone(),
137 81 : )
138 81 : };
139 81 :
140 81 : let timelines_dir = conf.tenant_dir(&tenant_id);
141 84 : for timelines_dir_entry in std::fs::read_dir(&timelines_dir)
142 81 : .with_context(|| format!("failed to list timelines dir {}", timelines_dir))?
143 : {
144 84 : match &timelines_dir_entry {
145 84 : Ok(timeline_dir_entry) => {
146 84 : if let Ok(timeline_id) =
147 84 : TimelineId::from_str(timeline_dir_entry.file_name().to_str().unwrap_or(""))
148 : {
149 84 : let ttid = TenantTimelineId::new(tenant_id, timeline_id);
150 84 : match Timeline::load_timeline(&conf, ttid, wal_backup_launcher_tx.clone()) {
151 84 : Ok(timeline) => {
152 84 : let tli = Arc::new(timeline);
153 84 : TIMELINES_STATE
154 84 : .lock()
155 84 : .unwrap()
156 84 : .timelines
157 84 : .insert(ttid, tli.clone());
158 84 : tli.bootstrap(&conf);
159 84 : tli.update_status_notify().await.unwrap();
160 : }
161 : // If we can't load a timeline, it's most likely because of a corrupted
162 : // directory. We will log an error and won't allow to delete/recreate
163 : // this timeline. The only way to fix this timeline is to repair manually
164 : // and restart the safekeeper.
165 UBC 0 : Err(e) => error!(
166 0 : "failed to load timeline {} for tenant {}, reason: {:?}",
167 0 : timeline_id, tenant_id, e
168 0 : ),
169 : }
170 0 : }
171 : }
172 0 : Err(e) => error!(
173 0 : "failed to list timelines dir entry {:?} in directory {}, reason: {:?}",
174 0 : timelines_dir_entry, timelines_dir, e
175 0 : ),
176 : }
177 : }
178 :
179 CBC 81 : Ok(())
180 81 : }
181 :
182 : /// Take a lock for timeline loading.
183 49 : pub async fn loading_lock() -> Arc<tokio::sync::Mutex<TimelineLoadLock>> {
184 49 : TIMELINES_STATE.lock().unwrap().load_lock.clone()
185 49 : }
186 :
187 : /// Load timeline from disk to the memory.
188 49 : pub async fn load_timeline<'a>(
189 49 : _guard: &tokio::sync::MutexGuard<'a, TimelineLoadLock>,
190 49 : ttid: TenantTimelineId,
191 49 : ) -> Result<Arc<Timeline>> {
192 49 : let (conf, wal_backup_launcher_tx) = TIMELINES_STATE.lock().unwrap().get_dependencies();
193 49 :
194 49 : match Timeline::load_timeline(&conf, ttid, wal_backup_launcher_tx) {
195 49 : Ok(timeline) => {
196 49 : let tli = Arc::new(timeline);
197 49 :
198 49 : // TODO: prevent concurrent timeline creation/loading
199 49 : TIMELINES_STATE
200 49 : .lock()
201 49 : .unwrap()
202 49 : .timelines
203 49 : .insert(ttid, tli.clone());
204 49 :
205 49 : tli.bootstrap(&conf);
206 49 :
207 49 : Ok(tli)
208 : }
209 : // If we can't load a timeline, it's bad. Caller will figure it out.
210 UBC 0 : Err(e) => bail!("failed to load timeline {}, reason: {:?}", ttid, e),
211 : }
212 CBC 49 : }
213 :
214 : /// Get the number of timelines in the map.
215 5 : pub fn timelines_count() -> usize {
216 5 : TIMELINES_STATE.lock().unwrap().timelines.len()
217 5 : }
218 :
219 : /// Get the global safekeeper config.
220 118 : pub fn get_global_config() -> SafeKeeperConf {
221 118 : TIMELINES_STATE.lock().unwrap().get_conf().clone()
222 118 : }
223 :
224 : /// Create a new timeline with the given id. If the timeline already exists, returns
225 : /// an existing timeline.
226 1751 : pub async fn create(
227 1751 : ttid: TenantTimelineId,
228 1751 : server_info: ServerInfo,
229 1751 : commit_lsn: Lsn,
230 1751 : local_start_lsn: Lsn,
231 1751 : ) -> Result<Arc<Timeline>> {
232 449 : let (conf, wal_backup_launcher_tx) = {
233 1751 : let state = TIMELINES_STATE.lock().unwrap();
234 1751 : if let Ok(timeline) = state.get(&ttid) {
235 : // Timeline already exists, return it.
236 1302 : return Ok(timeline);
237 449 : }
238 449 : state.get_dependencies()
239 : };
240 :
241 449 : info!("creating new timeline {}", ttid);
242 :
243 449 : let timeline = Arc::new(Timeline::create_empty(
244 449 : &conf,
245 449 : ttid,
246 449 : wal_backup_launcher_tx,
247 449 : server_info,
248 449 : commit_lsn,
249 449 : local_start_lsn,
250 449 : )?);
251 :
252 : // Take a lock and finish the initialization holding this mutex. No other threads
253 : // can interfere with creation after we will insert timeline into the map.
254 : {
255 449 : let mut shared_state = timeline.write_shared_state().await;
256 :
257 : // We can get a race condition here in case of concurrent create calls, but only
258 : // in theory. create() will return valid timeline on the next try.
259 449 : TIMELINES_STATE
260 449 : .lock()
261 449 : .unwrap()
262 449 : .try_insert(timeline.clone())?;
263 :
264 : // Write the new timeline to the disk and start background workers.
265 : // Bootstrap is transactional, so if it fails, the timeline will be deleted,
266 : // and the state on disk should remain unchanged.
267 2496 : if let Err(e) = timeline.init_new(&mut shared_state, &conf).await {
268 : // Note: the most likely reason for init failure is that the timeline
269 : // directory already exists on disk. This happens when timeline is corrupted
270 : // and wasn't loaded from disk on startup because of that. We want to preserve
271 : // the timeline directory in this case, for further inspection.
272 :
273 : // TODO: this is an unusual error, perhaps we should send it to sentry
274 : // TODO: compute will try to create timeline every second, we should add backoff
275 UBC 0 : error!("failed to init new timeline {}: {}", ttid, e);
276 :
277 : // Timeline failed to init, it cannot be used. Remove it from the map.
278 0 : TIMELINES_STATE.lock().unwrap().timelines.remove(&ttid);
279 0 : return Err(e);
280 CBC 449 : }
281 449 : // We are done with bootstrap, release the lock, return the timeline.
282 449 : // {} block forces release before .await
283 449 : }
284 449 : timeline.update_status_notify().await?;
285 449 : timeline.wal_backup_launcher_tx.send(timeline.ttid).await?;
286 449 : Ok(timeline)
287 1751 : }
288 :
289 : /// Get a timeline from the global map. If it's not present, it doesn't exist on disk,
290 : /// or was corrupted and couldn't be loaded on startup. Returned timeline is always valid,
291 : /// i.e. loaded in memory and not cancelled.
292 14669 : pub fn get(ttid: TenantTimelineId) -> Result<Arc<Timeline>, TimelineError> {
293 14669 : let res = TIMELINES_STATE.lock().unwrap().get(&ttid);
294 14669 :
295 14669 : match res {
296 14121 : Ok(tli) => {
297 14121 : if tli.is_cancelled() {
298 1 : return Err(TimelineError::Cancelled(ttid));
299 14120 : }
300 14120 : Ok(tli)
301 : }
302 548 : _ => res,
303 : }
304 14669 : }
305 :
306 : /// Returns all timelines. This is used for background timeline processes.
307 11343 : pub fn get_all() -> Vec<Arc<Timeline>> {
308 11343 : let global_lock = TIMELINES_STATE.lock().unwrap();
309 11343 : global_lock
310 11343 : .timelines
311 11343 : .values()
312 11343 : .filter(|t| !t.is_cancelled())
313 11343 : .cloned()
314 11343 : .collect()
315 11343 : }
316 :
317 : /// Returns all timelines belonging to a given tenant. Used for deleting all timelines of a tenant,
318 : /// and that's why it can return cancelled timelines, to retry deleting them.
319 4 : fn get_all_for_tenant(tenant_id: TenantId) -> Vec<Arc<Timeline>> {
320 4 : let global_lock = TIMELINES_STATE.lock().unwrap();
321 4 : global_lock
322 4 : .timelines
323 4 : .values()
324 20 : .filter(|t| t.ttid.tenant_id == tenant_id)
325 4 : .cloned()
326 4 : .collect()
327 4 : }
328 :
329 : /// Cancels timeline, then deletes the corresponding data directory.
330 27 : pub async fn delete_force(ttid: &TenantTimelineId) -> Result<TimelineDeleteForceResult> {
331 27 : let tli_res = TIMELINES_STATE.lock().unwrap().get(ttid);
332 27 : match tli_res {
333 25 : Ok(timeline) => {
334 : // Take a lock and finish the deletion holding this mutex.
335 25 : let mut shared_state = timeline.write_shared_state().await;
336 :
337 25 : info!("deleting timeline {}", ttid);
338 25 : let (dir_existed, was_active) =
339 25 : timeline.delete_from_disk(&mut shared_state).await?;
340 :
341 : // Remove timeline from the map.
342 : // FIXME: re-enable it once we fix the issue with recreation of deleted timelines
343 : // https://github.com/neondatabase/neon/issues/3146
344 : // TIMELINES_STATE.lock().unwrap().timelines.remove(ttid);
345 :
346 25 : Ok(TimelineDeleteForceResult {
347 25 : dir_existed,
348 25 : was_active,
349 25 : })
350 : }
351 : Err(_) => {
352 : // Timeline is not memory, but it may still exist on disk in broken state.
353 2 : let dir_path = TIMELINES_STATE
354 2 : .lock()
355 2 : .unwrap()
356 2 : .get_conf()
357 2 : .timeline_dir(ttid);
358 2 : let dir_existed = delete_dir(dir_path)?;
359 :
360 2 : Ok(TimelineDeleteForceResult {
361 2 : dir_existed,
362 2 : was_active: false,
363 2 : })
364 : }
365 : }
366 27 : }
367 :
368 : /// Deactivates and deletes all timelines for the tenant. Returns map of all timelines which
369 : /// the tenant had, `true` if a timeline was active. There may be a race if new timelines are
370 : /// created simultaneously. In that case the function will return error and the caller should
371 : /// retry tenant deletion again later.
372 4 : pub async fn delete_force_all_for_tenant(
373 4 : tenant_id: &TenantId,
374 4 : ) -> Result<HashMap<TenantTimelineId, TimelineDeleteForceResult>> {
375 4 : info!("deleting all timelines for tenant {}", tenant_id);
376 4 : let to_delete = Self::get_all_for_tenant(*tenant_id);
377 4 :
378 4 : let mut err = None;
379 4 :
380 4 : let mut deleted = HashMap::new();
381 20 : for tli in &to_delete {
382 16 : match Self::delete_force(&tli.ttid).await {
383 16 : Ok(result) => {
384 16 : deleted.insert(tli.ttid, result);
385 16 : }
386 UBC 0 : Err(e) => {
387 0 : error!("failed to delete timeline {}: {}", tli.ttid, e);
388 : // Save error to return later.
389 0 : err = Some(e);
390 : }
391 : }
392 : }
393 :
394 : // If there was an error, return it.
395 CBC 4 : if let Some(e) = err {
396 UBC 0 : return Err(e);
397 CBC 4 : }
398 4 :
399 4 : // There may be broken timelines on disk, so delete the whole tenant dir as well.
400 4 : // Note that we could concurrently create new timelines while we were deleting them,
401 4 : // so the directory may be not empty. In this case timelines will have bad state
402 4 : // and timeline background jobs can panic.
403 4 : delete_dir(
404 4 : TIMELINES_STATE
405 4 : .lock()
406 4 : .unwrap()
407 4 : .get_conf()
408 4 : .tenant_dir(tenant_id),
409 4 : )?;
410 :
411 : // FIXME: we temporarily disabled removing timelines from the map, see `delete_force`
412 : // let tlis_after_delete = Self::get_all_for_tenant(*tenant_id);
413 : // if !tlis_after_delete.is_empty() {
414 : // // Some timelines were created while we were deleting them, returning error
415 : // // to the caller, so it can retry later.
416 : // bail!(
417 : // "failed to delete all timelines for tenant {}: some timelines were created while we were deleting them",
418 : // tenant_id
419 : // );
420 : // }
421 :
422 4 : Ok(deleted)
423 4 : }
424 : }
425 :
426 27 : #[derive(Clone, Copy, Serialize)]
427 : pub struct TimelineDeleteForceResult {
428 : pub dir_existed: bool,
429 : pub was_active: bool,
430 : }
431 :
432 : /// Deletes directory and it's contents. Returns false if directory does not exist.
433 6 : fn delete_dir(path: Utf8PathBuf) -> Result<bool> {
434 6 : match std::fs::remove_dir_all(path) {
435 2 : Ok(_) => Ok(true),
436 4 : Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(false),
437 UBC 0 : Err(e) => Err(e.into()),
438 : }
439 CBC 6 : }
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