Line data Source code
1 : use std::ffi::OsStr;
2 : use std::path::{Path, PathBuf};
3 : use std::process::Command;
4 : use std::time::{Duration, Instant};
5 :
6 : use anyhow::{bail, ensure};
7 : use camino_tempfile::{Utf8TempDir, tempdir};
8 : use log::*;
9 : use postgres::Client;
10 : use postgres::types::PgLsn;
11 : use postgres_ffi::{
12 : PgMajorVersion, WAL_SEGMENT_SIZE, XLOG_BLCKSZ, XLOG_SIZE_OF_XLOG_LONG_PHD,
13 : XLOG_SIZE_OF_XLOG_RECORD, XLOG_SIZE_OF_XLOG_SHORT_PHD,
14 : };
15 :
16 : macro_rules! xlog_utils_test {
17 : ($version:ident) => {
18 : #[path = "."]
19 : mod $version {
20 : #[allow(unused_imports)]
21 : pub use postgres_ffi::$version::wal_craft_test_export::*;
22 : #[allow(clippy::duplicate_mod)]
23 : #[cfg(test)]
24 : mod xlog_utils_test;
25 : }
26 : };
27 : }
28 :
29 : postgres_ffi::for_all_postgres_versions! { xlog_utils_test }
30 :
31 : pub struct Conf {
32 : pub pg_version: PgMajorVersion,
33 : pub pg_distrib_dir: PathBuf,
34 : pub datadir: PathBuf,
35 : }
36 :
37 : pub struct PostgresServer {
38 : process: std::process::Child,
39 : _unix_socket_dir: Utf8TempDir,
40 : client_config: postgres::Config,
41 : }
42 :
43 : pub static REQUIRED_POSTGRES_CONFIG: [&str; 4] = [
44 : "wal_keep_size=50MB", // Ensure old WAL is not removed
45 : "shared_preload_libraries=neon", // can only be loaded at startup
46 : // Disable background processes as much as possible
47 : "wal_writer_delay=10s",
48 : "autovacuum=off",
49 : ];
50 :
51 : impl Conf {
52 108 : pub fn pg_distrib_dir(&self) -> anyhow::Result<PathBuf> {
53 108 : let path = self.pg_distrib_dir.clone();
54 :
55 108 : Ok(path.join(self.pg_version.v_str()))
56 108 : }
57 :
58 36 : fn pg_bin_dir(&self) -> anyhow::Result<PathBuf> {
59 36 : Ok(self.pg_distrib_dir()?.join("bin"))
60 36 : }
61 :
62 72 : fn pg_lib_dir(&self) -> anyhow::Result<PathBuf> {
63 72 : Ok(self.pg_distrib_dir()?.join("lib"))
64 72 : }
65 :
66 204 : pub fn wal_dir(&self) -> PathBuf {
67 204 : self.datadir.join("pg_wal")
68 204 : }
69 :
70 36 : fn new_pg_command(&self, command: impl AsRef<Path>) -> anyhow::Result<Command> {
71 36 : let path = self.pg_bin_dir()?.join(command);
72 36 : ensure!(path.exists(), "Command {:?} does not exist", path);
73 36 : let mut cmd = Command::new(path);
74 36 : cmd.env_clear()
75 36 : .env("LD_LIBRARY_PATH", self.pg_lib_dir()?)
76 36 : .env("DYLD_LIBRARY_PATH", self.pg_lib_dir()?)
77 36 : .env(
78 : "ASAN_OPTIONS",
79 36 : std::env::var("ASAN_OPTIONS").unwrap_or_default(),
80 : )
81 36 : .env(
82 : "UBSAN_OPTIONS",
83 36 : std::env::var("UBSAN_OPTIONS").unwrap_or_default(),
84 : );
85 36 : Ok(cmd)
86 36 : }
87 :
88 12 : pub fn initdb(&self) -> anyhow::Result<()> {
89 12 : if let Some(parent) = self.datadir.parent() {
90 12 : info!("Pre-creating parent directory {:?}", parent);
91 : // Tests may be run concurrently and there may be a race to create `test_output/`.
92 : // std::fs::create_dir_all is guaranteed to have no races with another thread creating directories.
93 12 : std::fs::create_dir_all(parent)?;
94 0 : }
95 12 : info!(
96 12 : "Running initdb in {:?} with user \"postgres\"",
97 : self.datadir
98 : );
99 12 : let output = self
100 12 : .new_pg_command("initdb")?
101 12 : .arg("--pgdata")
102 12 : .arg(&self.datadir)
103 12 : .args(["--username", "postgres", "--no-instructions", "--no-sync"])
104 12 : .output()?;
105 12 : debug!("initdb output: {:?}", output);
106 12 : ensure!(
107 12 : output.status.success(),
108 0 : "initdb failed, stdout and stderr follow:\n{}{}",
109 0 : String::from_utf8_lossy(&output.stdout),
110 0 : String::from_utf8_lossy(&output.stderr),
111 : );
112 12 : Ok(())
113 12 : }
114 :
115 12 : pub fn start_server(&self) -> anyhow::Result<PostgresServer> {
116 12 : info!("Starting Postgres server in {:?}", self.datadir);
117 12 : let unix_socket_dir = tempdir()?; // We need a directory with a short name for Unix socket (up to 108 symbols)
118 12 : let unix_socket_dir_path = unix_socket_dir.path().to_owned();
119 12 : let server_process = self
120 12 : .new_pg_command("postgres")?
121 12 : .args(["-c", "listen_addresses="])
122 12 : .arg("-k")
123 12 : .arg(&unix_socket_dir_path)
124 12 : .arg("-D")
125 12 : .arg(&self.datadir)
126 48 : .args(REQUIRED_POSTGRES_CONFIG.iter().flat_map(|cfg| ["-c", cfg]))
127 12 : .spawn()?;
128 12 : let server = PostgresServer {
129 12 : process: server_process,
130 12 : _unix_socket_dir: unix_socket_dir,
131 12 : client_config: {
132 12 : let mut c = postgres::Config::new();
133 12 : c.host_path(&unix_socket_dir_path);
134 12 : c.user("postgres");
135 12 : c.connect_timeout(Duration::from_millis(10000));
136 12 : c
137 12 : },
138 12 : };
139 12 : Ok(server)
140 12 : }
141 :
142 12 : pub fn pg_waldump(
143 12 : &self,
144 12 : first_segment_name: &OsStr,
145 12 : last_segment_name: &OsStr,
146 12 : ) -> anyhow::Result<std::process::Output> {
147 12 : let first_segment_file = self.datadir.join(first_segment_name);
148 12 : let last_segment_file = self.datadir.join(last_segment_name);
149 12 : info!(
150 12 : "Running pg_waldump for {} .. {}",
151 12 : first_segment_file.display(),
152 12 : last_segment_file.display()
153 : );
154 12 : let output = self
155 12 : .new_pg_command("pg_waldump")?
156 12 : .args([&first_segment_file, &last_segment_file])
157 12 : .output()?;
158 12 : debug!("waldump output: {:?}", output);
159 12 : Ok(output)
160 12 : }
161 : }
162 :
163 : impl PostgresServer {
164 12 : pub fn connect_with_timeout(&self) -> anyhow::Result<Client> {
165 12 : let retry_until = Instant::now() + *self.client_config.get_connect_timeout().unwrap();
166 33 : while Instant::now() < retry_until {
167 33 : if let Ok(client) = self.client_config.connect(postgres::NoTls) {
168 12 : return Ok(client);
169 21 : }
170 21 : std::thread::sleep(Duration::from_millis(100));
171 : }
172 0 : bail!("Connection timed out");
173 12 : }
174 :
175 12 : pub fn kill(mut self) {
176 12 : self.process.kill().unwrap();
177 12 : self.process.wait().unwrap();
178 12 : }
179 : }
180 :
181 : impl Drop for PostgresServer {
182 12 : fn drop(&mut self) {
183 12 : match self.process.try_wait() {
184 12 : Ok(Some(_)) => return,
185 : Ok(None) => {
186 0 : warn!("Server was not terminated, will be killed");
187 : }
188 0 : Err(e) => {
189 0 : error!("Unable to get status of the server: {}, will be killed", e);
190 : }
191 : }
192 0 : let _ = self.process.kill();
193 12 : }
194 : }
195 :
196 : pub trait PostgresClientExt: postgres::GenericClient {
197 24 : fn pg_current_wal_insert_lsn(&mut self) -> anyhow::Result<PgLsn> {
198 24 : Ok(self
199 24 : .query_one("SELECT pg_current_wal_insert_lsn()", &[])?
200 24 : .get(0))
201 24 : }
202 0 : fn pg_current_wal_flush_lsn(&mut self) -> anyhow::Result<PgLsn> {
203 0 : Ok(self
204 0 : .query_one("SELECT pg_current_wal_flush_lsn()", &[])?
205 0 : .get(0))
206 0 : }
207 : }
208 :
209 : impl<C: postgres::GenericClient> PostgresClientExt for C {}
210 :
211 12 : pub fn ensure_server_config(client: &mut impl postgres::GenericClient) -> anyhow::Result<()> {
212 12 : client.execute("create extension if not exists neon_test_utils", &[])?;
213 :
214 12 : let wal_keep_size: String = client.query_one("SHOW wal_keep_size", &[])?.get(0);
215 12 : ensure!(wal_keep_size == "50MB");
216 12 : let wal_writer_delay: String = client.query_one("SHOW wal_writer_delay", &[])?.get(0);
217 12 : ensure!(wal_writer_delay == "10s");
218 12 : let autovacuum: String = client.query_one("SHOW autovacuum", &[])?.get(0);
219 12 : ensure!(autovacuum == "off");
220 :
221 12 : let wal_segment_size = client.query_one(
222 12 : "select cast(setting as bigint) as setting, unit \
223 12 : from pg_settings where name = 'wal_segment_size'",
224 12 : &[],
225 0 : )?;
226 12 : ensure!(
227 12 : wal_segment_size.get::<_, String>("unit") == "B",
228 0 : "Unexpected wal_segment_size unit"
229 : );
230 12 : ensure!(
231 12 : wal_segment_size.get::<_, i64>("setting") == WAL_SEGMENT_SIZE as i64,
232 0 : "Unexpected wal_segment_size in bytes"
233 : );
234 :
235 12 : Ok(())
236 12 : }
237 :
238 : pub trait Crafter {
239 : const NAME: &'static str;
240 :
241 : /// Generates WAL using the client `client`. Returns a vector of some valid
242 : /// "interesting" intermediate LSNs which one may start reading from.
243 : /// test_end_of_wal uses this to check various starting points.
244 : ///
245 : /// Note that postgres is generally keen about writing some WAL. While we
246 : /// try to disable it (autovacuum, big wal_writer_delay, etc) it is always
247 : /// possible, e.g. xl_running_xacts are dumped each 15s. So checks about
248 : /// stable WAL end would be flaky unless postgres is shut down. For this
249 : /// reason returning potential end of WAL here is pointless. Most of the
250 : /// time this doesn't happen though, so it is reasonable to create needed
251 : /// WAL structure and immediately kill postgres like test_end_of_wal does.
252 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>>;
253 : }
254 :
255 : /// Wraps some WAL craft function, providing current LSN to it before the
256 : /// insertion and flushing WAL afterwards. Also pushes initial LSN to the
257 : /// result.
258 12 : fn craft_internal<C: postgres::GenericClient>(
259 12 : client: &mut C,
260 12 : f: impl Fn(&mut C, PgLsn) -> anyhow::Result<Vec<PgLsn>>,
261 12 : ) -> anyhow::Result<Vec<PgLsn>> {
262 12 : ensure_server_config(client)?;
263 :
264 12 : let initial_lsn = client.pg_current_wal_insert_lsn()?;
265 12 : info!("LSN initial = {}", initial_lsn);
266 :
267 12 : let mut intermediate_lsns = f(client, initial_lsn)?;
268 12 : if !intermediate_lsns.starts_with(&[initial_lsn]) {
269 12 : intermediate_lsns.insert(0, initial_lsn);
270 12 : }
271 :
272 : // Some records may be not flushed, e.g. non-transactional logical messages. Flush now.
273 : //
274 : // If the previous WAL record ended exactly at page boundary, pg_current_wal_insert_lsn
275 : // returns the position just after the page header on the next page. That's where the next
276 : // record will be inserted. But the page header hasn't actually been written to the WAL
277 : // yet, and if you try to flush it, you get a "request to flush past end of generated WAL"
278 : // error. Because of that, if the insert location is just after a page header, back off to
279 : // previous page boundary.
280 12 : let mut lsn = u64::from(client.pg_current_wal_insert_lsn()?);
281 12 : if lsn % WAL_SEGMENT_SIZE as u64 == XLOG_SIZE_OF_XLOG_LONG_PHD as u64 {
282 0 : lsn -= XLOG_SIZE_OF_XLOG_LONG_PHD as u64;
283 12 : } else if lsn % XLOG_BLCKSZ as u64 == XLOG_SIZE_OF_XLOG_SHORT_PHD as u64 {
284 0 : lsn -= XLOG_SIZE_OF_XLOG_SHORT_PHD as u64;
285 12 : }
286 12 : client.execute("select neon_xlogflush($1)", &[&PgLsn::from(lsn)])?;
287 12 : Ok(intermediate_lsns)
288 12 : }
289 :
290 : pub struct Simple;
291 : impl Crafter for Simple {
292 : const NAME: &'static str = "simple";
293 4 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>> {
294 4 : craft_internal(client, |client, _| {
295 4 : client.execute("CREATE table t(x int)", &[])?;
296 4 : Ok(Vec::new())
297 4 : })
298 4 : }
299 : }
300 :
301 : pub struct LastWalRecordXlogSwitch;
302 : impl Crafter for LastWalRecordXlogSwitch {
303 : const NAME: &'static str = "last_wal_record_xlog_switch";
304 0 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>> {
305 : // Do not use craft_internal because here we end up with flush_lsn exactly on
306 : // the segment boundary and insert_lsn after the initial page header, which is unusual.
307 0 : ensure_server_config(client)?;
308 :
309 0 : client.execute("CREATE table t(x int)", &[])?;
310 0 : let before_xlog_switch = client.pg_current_wal_insert_lsn()?;
311 : // pg_switch_wal returns end of last record of the switched segment,
312 : // i.e. end of SWITCH itself.
313 0 : let xlog_switch_record_end: PgLsn = client.query_one("SELECT pg_switch_wal()", &[])?.get(0);
314 0 : let before_xlog_switch_u64 = u64::from(before_xlog_switch);
315 0 : let next_segment = PgLsn::from(
316 0 : before_xlog_switch_u64 - (before_xlog_switch_u64 % WAL_SEGMENT_SIZE as u64)
317 0 : + WAL_SEGMENT_SIZE as u64,
318 : );
319 0 : ensure!(
320 0 : xlog_switch_record_end <= next_segment,
321 0 : "XLOG_SWITCH record ended after the expected segment boundary: {} > {}",
322 : xlog_switch_record_end,
323 : next_segment
324 : );
325 0 : Ok(vec![before_xlog_switch, xlog_switch_record_end])
326 0 : }
327 : }
328 :
329 : pub struct LastWalRecordXlogSwitchEndsOnPageBoundary;
330 : /// Craft xlog SWITCH record ending at page boundary.
331 : impl Crafter for LastWalRecordXlogSwitchEndsOnPageBoundary {
332 : const NAME: &'static str = "last_wal_record_xlog_switch_ends_on_page_boundary";
333 0 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>> {
334 : // Do not use generate_internal because here we end up with flush_lsn exactly on
335 : // the segment boundary and insert_lsn after the initial page header, which is unusual.
336 0 : ensure_server_config(client)?;
337 :
338 0 : client.execute("CREATE table t(x int)", &[])?;
339 :
340 : // Add padding so the XLOG_SWITCH record ends exactly on XLOG_BLCKSZ boundary. We
341 : // will use carefully-sized logical messages to advance WAL insert location such
342 : // that there is just enough space on the page for the XLOG_SWITCH record.
343 : loop {
344 : // We start with measuring how much WAL it takes for one logical message,
345 : // considering all alignments and headers.
346 0 : let before_lsn = client.pg_current_wal_insert_lsn()?;
347 0 : client.execute(
348 0 : "SELECT pg_logical_emit_message(false, 'swch', REPEAT('a', 10))",
349 0 : &[],
350 0 : )?;
351 0 : let after_lsn = client.pg_current_wal_insert_lsn()?;
352 :
353 : // Did the record cross a page boundary? If it did, start over. Crossing a
354 : // page boundary adds to the apparent size of the record because of the page
355 : // header, which throws off the calculation.
356 0 : if u64::from(before_lsn) / XLOG_BLCKSZ as u64
357 0 : != u64::from(after_lsn) / XLOG_BLCKSZ as u64
358 : {
359 0 : continue;
360 0 : }
361 : // base_size is the size of a logical message without the payload
362 0 : let base_size = u64::from(after_lsn) - u64::from(before_lsn) - 10;
363 :
364 : // Is there enough space on the page for another logical message and an
365 : // XLOG_SWITCH? If not, start over.
366 0 : let page_remain = XLOG_BLCKSZ as u64 - u64::from(after_lsn) % XLOG_BLCKSZ as u64;
367 0 : if page_remain < base_size + XLOG_SIZE_OF_XLOG_RECORD as u64 {
368 0 : continue;
369 0 : }
370 :
371 : // We will write another logical message, such that after the logical message
372 : // record, there will be space for exactly one XLOG_SWITCH. How large should
373 : // the logical message's payload be? An XLOG_SWITCH record has no data => its
374 : // size is exactly XLOG_SIZE_OF_XLOG_RECORD.
375 0 : let repeats = page_remain - base_size - XLOG_SIZE_OF_XLOG_RECORD as u64;
376 :
377 0 : client.execute(
378 0 : "SELECT pg_logical_emit_message(false, 'swch', REPEAT('a', $1))",
379 0 : &[&(repeats as i32)],
380 0 : )?;
381 0 : info!(
382 0 : "current_wal_insert_lsn={}, XLOG_SIZE_OF_XLOG_RECORD={}",
383 0 : client.pg_current_wal_insert_lsn()?,
384 : XLOG_SIZE_OF_XLOG_RECORD
385 : );
386 :
387 : // Emit the XLOG_SWITCH
388 0 : let before_xlog_switch = client.pg_current_wal_insert_lsn()?;
389 0 : let xlog_switch_record_end: PgLsn =
390 0 : client.query_one("SELECT pg_switch_wal()", &[])?.get(0);
391 :
392 0 : if u64::from(xlog_switch_record_end) as usize % XLOG_BLCKSZ
393 0 : != XLOG_SIZE_OF_XLOG_SHORT_PHD
394 : {
395 0 : warn!(
396 0 : "XLOG_SWITCH message ended not on page boundary: {}, offset = {}, repeating",
397 : xlog_switch_record_end,
398 0 : u64::from(xlog_switch_record_end) as usize % XLOG_BLCKSZ
399 : );
400 0 : continue;
401 0 : }
402 0 : return Ok(vec![before_xlog_switch, xlog_switch_record_end]);
403 : }
404 0 : }
405 : }
406 :
407 : /// Write ~16MB logical message; it should cross WAL segment.
408 8 : fn craft_seg_size_logical_message(
409 8 : client: &mut impl postgres::GenericClient,
410 8 : transactional: bool,
411 8 : ) -> anyhow::Result<Vec<PgLsn>> {
412 8 : craft_internal(client, |client, initial_lsn| {
413 8 : ensure!(
414 8 : initial_lsn < PgLsn::from(0x0200_0000 - 1024 * 1024),
415 0 : "Initial LSN is too far in the future"
416 : );
417 :
418 8 : let message_lsn: PgLsn = client
419 8 : .query_one(
420 8 : "select pg_logical_emit_message($1, 'big-16mb-msg', \
421 8 : concat(repeat('abcd', 16 * 256 * 1024), 'end')) as message_lsn",
422 8 : &[&transactional],
423 0 : )?
424 8 : .get("message_lsn");
425 8 : ensure!(
426 8 : message_lsn > PgLsn::from(0x0200_0000 + 4 * 8192),
427 0 : "Logical message did not cross the segment boundary"
428 : );
429 8 : ensure!(
430 8 : message_lsn < PgLsn::from(0x0400_0000),
431 0 : "Logical message crossed two segments"
432 : );
433 :
434 8 : Ok(vec![message_lsn])
435 8 : })
436 8 : }
437 :
438 : pub struct WalRecordCrossingSegmentFollowedBySmallOne;
439 : impl Crafter for WalRecordCrossingSegmentFollowedBySmallOne {
440 : const NAME: &'static str = "wal_record_crossing_segment_followed_by_small_one";
441 4 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>> {
442 : // Transactional message crossing WAL segment will be followed by small
443 : // commit record.
444 4 : craft_seg_size_logical_message(client, true)
445 4 : }
446 : }
447 :
448 : pub struct LastWalRecordCrossingSegment;
449 : impl Crafter for LastWalRecordCrossingSegment {
450 : const NAME: &'static str = "last_wal_record_crossing_segment";
451 4 : fn craft(client: &mut impl postgres::GenericClient) -> anyhow::Result<Vec<PgLsn>> {
452 4 : craft_seg_size_logical_message(client, false)
453 4 : }
454 : }
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