Rename wal_acceptor binary to safekeeper (#740), stage 1/2

* Rename wal_acceptor binary to safekeeper
* Rename wal_acceptor.pid and wal_acceptor.log to safekeeper.pid and safekeeper.log
* Change some mentions of WAL acceptor to safekeeper
* Dockerfile: alias wal_acceptor to safekeeper temporarily until internal scripts are updated

.circleci/config.yml

@@ -260,7 +260,7 @@ jobs:
           when: always
           command: |
             du -sh /tmp/test_output/*
-            find /tmp/test_output -type f ! -name "pg.log" ! -name "pageserver.log" ! -name "wal_acceptor.log" ! -name "regression.diffs" ! -name "junit.xml" ! -name "*.filediff" ! -name "*.stdout" ! -name "*.stderr" -delete
+            find /tmp/test_output -type f ! -name "pg.log" ! -name "pageserver.log" ! -name "safekeeper.log" ! -name "regression.diffs" ! -name "junit.xml" ! -name "*.filediff" ! -name "*.stdout" ! -name "*.stderr" -delete
             du -sh /tmp/test_output/*
       - store_artifacts:
           path: /tmp/test_output

Dockerfile

@@ -37,7 +37,9 @@ RUN apt-get update && apt-get -yq install libreadline-dev libseccomp-dev openssl
     mkdir zenith_install
 
 COPY --from=build /zenith/target/release/pageserver /usr/local/bin
-COPY --from=build /zenith/target/release/wal_acceptor /usr/local/bin
+COPY --from=build /zenith/target/release/safekeeper /usr/local/bin
+# TODO: temporary alias for compatibility, see https://github.com/zenithdb/zenith/pull/740
+RUN ln -s /usr/local/bin/safekeeper /usr/local/bin/wal_acceptor
 COPY --from=build /zenith/target/release/proxy /usr/local/bin
 COPY --from=pg-build /zenith/tmp_install postgres_install
 COPY docker-entrypoint.sh /docker-entrypoint.sh

Dockerfile.alpine

@@ -81,7 +81,9 @@ FROM alpine:3.13
 RUN apk add --update openssl build-base libseccomp-dev
 RUN apk --no-cache --update --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing add rocksdb
 COPY --from=build /zenith/target/release/pageserver /usr/local/bin
-COPY --from=build /zenith/target/release/wal_acceptor /usr/local/bin
+COPY --from=build /zenith/target/release/safekeeper /usr/local/bin
+# TODO: temporary alias for compatibility, see https://github.com/zenithdb/zenith/pull/740
+RUN ln -s /usr/local/bin/safekeeper /usr/local/bin/wal_acceptor
 COPY --from=build /zenith/target/release/proxy /usr/local/bin
 COPY --from=pg-build /zenith/tmp_install /usr/local
 COPY docker-entrypoint.sh /docker-entrypoint.sh

docs/docker.md

@@ -4,7 +4,7 @@
 
 Currently we build two main images:
 
-- [zenithdb/zenith](https://hub.docker.com/repository/docker/zenithdb/zenith) — image with pre-built `pageserver`, `wal_acceptor` and `proxy` binaries and all the required runtime dependencies. Built from [/Dockerfile](/Dockerfile).
+- [zenithdb/zenith](https://hub.docker.com/repository/docker/zenithdb/zenith) — image with pre-built `pageserver`, `safekeeper` and `proxy` binaries and all the required runtime dependencies. Built from [/Dockerfile](/Dockerfile).
 - [zenithdb/compute-node](https://hub.docker.com/repository/docker/zenithdb/compute-node) — compute node image with pre-built Postgres binaries from [zenithdb/postgres](https://github.com/zenithdb/postgres).
 
 And two intermediate images used either to reduce build time or to deliver some additional binary tools from other repos:

docs/multitenancy.md

@@ -56,4 +56,4 @@ Tenant id is passed to postgres via GUC the same way as the timeline. Tenant id
 
 ### Safety
 
-For now particular tenant can only appear on a particular pageserver. Set of WAL acceptors are also pinned to particular (tenantid, timeline) pair so there can only be one writer for particular (tenantid, timeline).
+For now particular tenant can only appear on a particular pageserver. Set of safekeepers are also pinned to particular (tenantid, timeline) pair so there can only be one writer for particular (tenantid, timeline).

test_runner/fixtures/zenith_fixtures.py

@@ -64,7 +64,7 @@ def pytest_configure(config):
          raise Exception('Too many workers configured. Cannot distrubute ports for services.')
 
     # does not use -c as it is not supported on macOS
-    cmd = ['pgrep', 'pageserver|postgres|wal_acceptor']
+    cmd = ['pgrep', 'pageserver|postgres|safekeeper']
     result = subprocess.run(cmd, stdout=subprocess.DEVNULL)
     if result.returncode == 0:
         # returncode of 0 means it found something.
@@ -72,7 +72,7 @@ def pytest_configure(config):
         # result of the test.
         # NOTE this shows as an internal pytest error, there might be a better way
         raise Exception(
-            'Found interfering processes running. Stop all Zenith pageservers, nodes, WALs, as well as stand-alone Postgres.'
+            'Found interfering processes running. Stop all Zenith pageservers, nodes, safekeepers, as well as stand-alone Postgres.'
         )
 
 
@@ -843,7 +843,7 @@ class WalAcceptor:
 
     @property
     def pidfile(self) -> Path:
-        return self.data_dir / "wal_acceptor.pid"
+        return self.data_dir / "safekeeper.pid"
 
     def get_pid(self) -> Optional[int]:
         if not self.pidfile.exists():
@@ -895,7 +895,7 @@ class WalAcceptor:
 class WalAcceptorFactory:
     """ An object representing multiple running wal acceptors. """
     def __init__(self, zenith_binpath: Path, data_dir: Path, pageserver_port: int, port_distributor: PortDistributor):
-        self.wa_bin_path = zenith_binpath / 'wal_acceptor'
+        self.wa_bin_path = zenith_binpath / 'safekeeper'
         self.data_dir = data_dir
         self.instances: List[WalAcceptor] = []
         self.port_distributor = port_distributor

walkeeper/src/bin/safekeeper.rs

@@ -1,5 +1,5 @@
 //
-// Main entry point for the wal_acceptor executable
+// Main entry point for the safekeeper executable
 //
 use anyhow::Result;
 use clap::{App, Arg};
@@ -20,14 +20,14 @@ use walkeeper::WalAcceptorConf;
 
 fn main() -> Result<()> {
     zenith_metrics::set_common_metrics_prefix("safekeeper");
-    let arg_matches = App::new("Zenith wal_acceptor")
+    let arg_matches = App::new("Zenith safekeeper")
         .about("Store WAL stream to local file system and push it to WAL receivers")
         .arg(
             Arg::with_name("datadir")
                 .short("D")
                 .long("dir")
                 .takes_value(true)
-                .help("Path to the WAL acceptor data directory"),
+                .help("Path to the safekeeper data directory"),
         )
         .arg(
             Arg::with_name("listen-pg")
@@ -128,7 +128,7 @@ fn main() -> Result<()> {
 }
 
 fn start_wal_acceptor(conf: WalAcceptorConf) -> Result<()> {
-    let log_filename = conf.data_dir.join("wal_acceptor.log");
+    let log_filename = conf.data_dir.join("safekeeper.log");
     let log_file = logging::init(log_filename, conf.daemonize)?;
 
     let http_listener = TcpListener::bind(conf.listen_http_addr.clone()).map_err(|e| {
@@ -136,7 +136,7 @@ fn start_wal_acceptor(conf: WalAcceptorConf) -> Result<()> {
         e
     })?;
 
-    info!("Starting wal acceptor on {}", conf.listen_pg_addr);
+    info!("Starting safekeeper on {}", conf.listen_pg_addr);
     let pg_listener = TcpListener::bind(conf.listen_pg_addr.clone()).map_err(|e| {
         error!("failed to bind to address {}: {}", conf.listen_pg_addr, e);
         e
@@ -151,7 +151,7 @@ fn start_wal_acceptor(conf: WalAcceptorConf) -> Result<()> {
         let stderr = log_file;
 
         let daemonize = Daemonize::new()
-            .pid_file("wal_acceptor.pid")
+            .pid_file("safekeeper.pid")
             .working_directory(Path::new("."))
             .stdout(stdout)
             .stderr(stderr);

walkeeper/src/send_wal.rs

@@ -20,7 +20,6 @@ use crate::timeline::CreateControlFile;
 
 /// Handler for streaming WAL from acceptor
 pub struct SendWalHandler {
-    /// wal acceptor configuration
     pub conf: WalAcceptorConf,
     /// assigned application name
     pub appname: Option<String>,

walkeeper/src/timeline.rs

@@ -112,7 +112,7 @@ impl SharedState {
         }
         match opts.open(&control_file_path) {
             Ok(mut file) => {
-                // Lock file to prevent two or more active wal_acceptors
+                // Lock file to prevent two or more active safekeepers
                 match file.try_lock_exclusive() {
                     Ok(()) => {}
                     Err(e) => {

walkeeper/src/wal_service.rs

@@ -36,7 +36,7 @@ fn handle_socket(socket: TcpStream, conf: WalAcceptorConf) -> Result<()> {
 
     let mut conn_handler = SendWalHandler::new(conf);
     let pgbackend = PostgresBackend::new(socket, AuthType::Trust, None, false)?;
-    // libpq replication protocol between wal_acceptor and replicas/pagers
+    // libpq replication protocol between safekeeper and replicas/pagers
     pgbackend.run(&mut conn_handler)?;
 
     Ok(())