basebackup_progress.c

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/*-------------------------------------------------------------------------
 *
 * basebackup_progress.c
 *    Basebackup sink implementing progress tracking, including but not
 *    limited to command progress reporting.
 *
 * This should be used even if the PROGRESS option to the replication
 * command BASE_BACKUP is not specified. Without that option, we won't
 * have tallied up the size of the files that are going to need to be
 * backed up, but we can still report to the command progress reporting
 * facility how much data we've processed.
 *
 * Moreover, we also use this as a convenient place to update certain
 * fields of the bbsink_state. That work is accurately described as
 * keeping track of our progress, but it's not just for introspection.
 * We need those fields to be updated properly in order for base backups
 * to work.
 *
 * This particular basebackup sink requires extra callbacks that most base
 * backup sinks don't. Rather than cramming those into the interface, we just
 * have a few extra functions here that basebackup.c can call. (We could put
 * the logic directly into that file as it's fairly simple, but it seems
 * cleaner to have everything related to progress reporting in one place.)
 *
 * Portions Copyright (c) 2010-2023, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *    src/backend/backup/basebackup_progress.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include "backup/basebackup.h"
#include "backup/basebackup_sink.h"
#include "commands/progress.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "storage/latch.h"
#include "utils/timestamp.h"
 
static void bbsink_progress_begin_backup(bbsink *sink);
static void bbsink_progress_archive_contents(bbsink *sink, size_t len);
static void bbsink_progress_end_archive(bbsink *sink);
 
static const bbsink_ops bbsink_progress_ops = {
    .begin_backup = bbsink_progress_begin_backup,
    .begin_archive = bbsink_forward_begin_archive,
    .archive_contents = bbsink_progress_archive_contents,
    .end_archive = bbsink_progress_end_archive,
    .begin_manifest = bbsink_forward_begin_manifest,
    .manifest_contents = bbsink_forward_manifest_contents,
    .end_manifest = bbsink_forward_end_manifest,
    .end_backup = bbsink_forward_end_backup,
    .cleanup = bbsink_forward_cleanup
};
 
/*
 * Create a new basebackup sink that performs progress tracking functions and
 * forwards data to a successor sink.
 */
bbsink *
bbsink_progress_new(bbsink *next, bool estimate_backup_size)
{
    bbsink     *sink;
 
    Assert(next != NULL);
 
    sink = palloc0(sizeof(bbsink));
    *((const bbsink_ops **) &sink->bbs_ops) = &bbsink_progress_ops;
    sink->bbs_next = next;
 
    /*
     * Report that a base backup is in progress, and set the total size of the
     * backup to -1, which will get translated to NULL. If we're estimating
     * the backup size, we'll insert the real estimate when we have it.
     */
    pgstat_progress_start_command(PROGRESS_COMMAND_BASEBACKUP, InvalidOid);
    pgstat_progress_update_param(PROGRESS_BASEBACKUP_BACKUP_TOTAL, -1);
 
    return sink;
}
 
/*
 * Progress reporting at start of backup.
 */
static void
bbsink_progress_begin_backup(bbsink *sink)
{
    const int   index[] = {
        PROGRESS_BASEBACKUP_PHASE,
        PROGRESS_BASEBACKUP_BACKUP_TOTAL,
        PROGRESS_BASEBACKUP_TBLSPC_TOTAL
    };
    int64       val[3];
 
    /*
     * Report that we are now streaming database files as a base backup. Also
     * advertise the number of tablespaces, and, if known, the estimated total
     * backup size.
     */
    val[0] = PROGRESS_BASEBACKUP_PHASE_STREAM_BACKUP;
    if (sink->bbs_state->bytes_total_is_valid)
        val[1] = sink->bbs_state->bytes_total;
    else
        val[1] = -1;
    val[2] = list_length(sink->bbs_state->tablespaces);
    pgstat_progress_update_multi_param(3, index, val);
 
    /* Delegate to next sink. */
    bbsink_forward_begin_backup(sink);
}
 
/*
 * End-of archive progress reporting.
 */
static void
bbsink_progress_end_archive(bbsink *sink)
{
    /*
     * We expect one archive per tablespace, so reaching the end of an archive
     * also means reaching the end of a tablespace. (Some day we might have a
     * reason to decouple these concepts.)
     *
     * If WAL is included in the backup, we'll mark the last tablespace
     * complete before the last archive is complete, so we need a guard here
     * to ensure that the number of tablespaces streamed doesn't exceed the
     * total.
     */
    if (sink->bbs_state->tablespace_num < list_length(sink->bbs_state->tablespaces))
        pgstat_progress_update_param(PROGRESS_BASEBACKUP_TBLSPC_STREAMED,
                                     sink->bbs_state->tablespace_num + 1);
 
    /* Delegate to next sink. */
    bbsink_forward_end_archive(sink);
 
    /*
     * This is a convenient place to update the bbsink_state's notion of which
     * is the current tablespace. Note that the bbsink_state object is shared
     * across all bbsink objects involved, but we're the outermost one and
     * this is the very last thing we do.
     */
    sink->bbs_state->tablespace_num++;
}
 
/*
 * Handle progress tracking for new archive contents.
 *
 * Increment the counter for the amount of data already streamed
 * by the given number of bytes, and update the progress report for
 * pg_stat_progress_basebackup.
 */
static void
bbsink_progress_archive_contents(bbsink *sink, size_t len)
{
    bbsink_state *state = sink->bbs_state;
    const int   index[] = {
        PROGRESS_BASEBACKUP_BACKUP_STREAMED,
        PROGRESS_BASEBACKUP_BACKUP_TOTAL
    };
    int64       val[2];
    int         nparam = 0;
 
    /* First update bbsink_state with # of bytes done. */
    state->bytes_done += len;
 
    /* Now forward to next sink. */
    bbsink_forward_archive_contents(sink, len);
 
    /* Prepare to set # of bytes done for command progress reporting. */
    val[nparam++] = state->bytes_done;
 
    /*
     * We may also want to update # of total bytes, to avoid overflowing past
     * 100% or the full size. This may make the total size number change as we
     * approach the end of the backup (the estimate will always be wrong if
     * WAL is included), but that's better than having the done column be
     * bigger than the total.
     */
    if (state->bytes_total_is_valid && state->bytes_done > state->bytes_total)
        val[nparam++] = state->bytes_done;
 
    pgstat_progress_update_multi_param(nparam, index, val);
}
 
/*
 * Advertise that we are waiting for the start-of-backup checkpoint.
 */
void
basebackup_progress_wait_checkpoint(void)
{
    pgstat_progress_update_param(PROGRESS_BASEBACKUP_PHASE,
                                 PROGRESS_BASEBACKUP_PHASE_WAIT_CHECKPOINT);
}
 
/*
 * Advertise that we are estimating the backup size.
 */
void
basebackup_progress_estimate_backup_size(void)
{
    pgstat_progress_update_param(PROGRESS_BASEBACKUP_PHASE,
                                 PROGRESS_BASEBACKUP_PHASE_ESTIMATE_BACKUP_SIZE);
}
 
/*
 * Advertise that we are waiting for WAL archiving at end-of-backup.
 */
void
basebackup_progress_wait_wal_archive(bbsink_state *state)
{
    const int   index[] = {
        PROGRESS_BASEBACKUP_PHASE,
        PROGRESS_BASEBACKUP_TBLSPC_STREAMED
    };
    int64       val[2];
 
    /*
     * We report having finished all tablespaces at this point, even if the
     * archive for the main tablespace is still open, because what's going to
     * be added is WAL files, not files that are really from the main
     * tablespace.
     */
    val[0] = PROGRESS_BASEBACKUP_PHASE_WAIT_WAL_ARCHIVE;
    val[1] = list_length(state->tablespaces);
    pgstat_progress_update_multi_param(2, index, val);
}
 
/*
 * Advertise that we are transferring WAL files into the final archive.
 */
void
basebackup_progress_transfer_wal(void)
{
    pgstat_progress_update_param(PROGRESS_BASEBACKUP_PHASE,
                                 PROGRESS_BASEBACKUP_PHASE_TRANSFER_WAL);
}
 
/*
 * Advertise that we are no longer performing a backup.
 */
void
basebackup_progress_done(void)
{
    pgstat_progress_end_command();
}