Files
neon/compute_tools/src/zenith.rs

108 lines
3.3 KiB
Rust

use std::process::{Command, Stdio};
use anyhow::Result;
use chrono::{DateTime, Utc};
use postgres::{Client, NoTls};
use serde::Deserialize;
use crate::pg_helpers::*;
/// Compute node state shared across several `zenith_ctl` threads.
/// Should be used under `RwLock` to allow HTTP API server to serve
/// status requests, while configuration is in progress.
pub struct ComputeState {
pub connstr: String,
pub pgdata: String,
pub pgbin: String,
pub spec: ClusterSpec,
/// Compute setup process has finished
pub ready: bool,
/// Timestamp of the last Postgres activity
pub last_active: DateTime<Utc>,
}
/// Cluster spec or configuration represented as an optional number of
/// delta operations + final cluster state description.
#[derive(Clone, Deserialize)]
pub struct ClusterSpec {
pub format_version: f32,
pub timestamp: String,
pub operation_uuid: Option<String>,
/// Expected cluster state at the end of transition process.
pub cluster: Cluster,
pub delta_operations: Option<Vec<DeltaOp>>,
}
/// Cluster state seen from the perspective of the external tools
/// like Rails web console.
#[derive(Clone, Deserialize)]
pub struct Cluster {
pub cluster_id: String,
pub name: String,
pub state: Option<String>,
pub roles: Vec<Role>,
pub databases: Vec<Database>,
pub settings: GenericOptions,
}
/// Single cluster state changing operation that could not be represented as
/// a static `Cluster` structure. For example:
/// - DROP DATABASE
/// - DROP ROLE
/// - ALTER ROLE name RENAME TO new_name
/// - ALTER DATABASE name RENAME TO new_name
#[derive(Clone, Deserialize)]
pub struct DeltaOp {
pub action: String,
pub name: PgIdent,
pub new_name: Option<PgIdent>,
}
/// Get basebackup from the libpq connection to pageserver using `connstr` and
/// unarchive it to `pgdata` directory overriding all its previous content.
pub fn get_basebackup(
pgdata: &str,
connstr: &str,
tenant: &str,
timeline: &str,
lsn: &str,
) -> Result<()> {
let mut client = Client::connect(connstr, NoTls)?;
let basebackup_cmd = match lsn {
"0/0" => format!("basebackup {} {}", tenant, timeline), // First start of the compute
_ => format!("basebackup {} {} {}", tenant, timeline, lsn),
};
let copyreader = client.copy_out(basebackup_cmd.as_str())?;
let mut ar = tar::Archive::new(copyreader);
ar.unpack(&pgdata)?;
Ok(())
}
/// Run `postgres` in a special mode with `--sync-safekeepers` argument
/// and return the reported LSN back to the caller.
pub fn sync_safekeepers(pgdata: &str, pgbin: &str) -> Result<String> {
let sync_handle = Command::new(&pgbin)
.args(&["--sync-safekeepers"])
.env("PGDATA", &pgdata) // we cannot use -D in this mode
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.spawn()
.expect("postgres --sync-safekeepers failed to start");
let sync_output = sync_handle
.wait_with_output()
.expect("postgres --sync-safekeepers failed");
if !sync_output.status.success() {
anyhow::bail!(
"postgres --sync-safekeepers failed: '{}'",
String::from_utf8_lossy(&sync_output.stderr)
);
}
let lsn = String::from(String::from_utf8(sync_output.stdout)?.trim());
Ok(lsn)
}