diff --git a/addons/mongodb/dataprotection/backup-info-collector.sh b/addons/mongodb/dataprotection/backup-info-collector.sh
index 8cb75b0119..919ac5ac6b 100644
--- a/addons/mongodb/dataprotection/backup-info-collector.sh
+++ b/addons/mongodb/dataprotection/backup-info-collector.sh
@@ -1,25 +1,132 @@
 # shellcheck disable=SC2148
 function get_current_time() {
-  if [ -n "$(whereis mongosh | awk '{print $2}')" ]; then
-    CLIENT="mongosh"
+  local client curr_time status
+
+  if command -v mongosh >/dev/null 2>&1; then
+    client="mongosh"
+  elif command -v mongo >/dev/null 2>&1; then
+    client="mongo"
+  else
+    printf 'backup info timestamp client unavailable rc=127\n' >&2
+    return 127
+  fi
+
+  if curr_time=$(
+    "$client" \
+      -u "$DP_DB_USER" \
+      -p "$DP_DB_PASSWORD" \
+      --port "$DP_DB_PORT" \
+      --host "$DP_DB_HOST" \
+      --authenticationDatabase admin \
+      --eval 'db.isMaster().lastWrite.lastWriteDate.getTime()/1000' \
+      --quiet
+  ); then
+    :
   else
-    CLIENT="mongo"
+    status=$?
+    printf 'backup info timestamp client failed rc=%s\n' "$status" >&2
+    return "$status"
   fi
-  curr_time=$(${CLIENT} -u ${DP_DB_USER} -p ${DP_DB_PASSWORD} --port ${DP_DB_PORT} --host ${DP_DB_HOST} --authenticationDatabase admin --eval 'db.isMaster().lastWrite.lastWriteDate.getTime()/1000' --quiet)
-  curr_time=$(date -d "@${curr_time}" -u '+%Y-%m-%dT%H:%M:%SZ')
-  echo $curr_time
+
+  if [ -z "$curr_time" ]; then
+    printf 'backup info timestamp client returned empty output rc=65\n' >&2
+    return 65
+  fi
+
+  if curr_time=$(date -d "@${curr_time}" -u '+%Y-%m-%dT%H:%M:%SZ'); then
+    :
+  else
+    status=$?
+    printf 'backup info timestamp conversion failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if [ -z "$curr_time" ]; then
+    printf 'backup info timestamp conversion returned empty output rc=65\n' >&2
+    return 65
+  fi
+
+  printf '%s\n' "$curr_time"
 }
 
 function stat_and_save_backup_info() {
+  local start_time stop_time stat_output status total_size tmp_file
+
   export PATH="$PATH:$DP_DATASAFED_BIN_PATH"
   export DATASAFED_BACKEND_BASE_PATH="$DP_BACKUP_BASE_PATH"
-  START_TIME=$1
-  STOP_TIME=$2
-  if [ -z $STOP_TIME ]; then
-    STOP_TIME=$(get_current_time)
+
+  start_time=${1:-}
+  stop_time=${2:-}
+  if [ -z "$stop_time" ]; then
+    if stop_time=$(get_current_time); then
+      :
+    else
+      status=$?
+      printf 'backup info stop timestamp failed rc=%s\n' "$status" >&2
+      return "$status"
+    fi
+  fi
+
+  if stat_output=$(datasafed stat /); then
+    :
+  else
+    status=$?
+    printf 'backup info datasafed stat failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if total_size=$(
+    printf '%s\n' "$stat_output" |
+      awk '
+        $1 == "TotalSize:" {
+          count++
+          if (NF == 2 && $2 ~ /^[0-9]+$/) {
+            valid++
+            value = $2
+          }
+        }
+        END {
+          if (count == 1 && valid == 1) {
+            print value
+            exit 0
+          }
+          exit 65
+        }
+      '
+  ); then
+    :
+  else
+    printf 'backup info TotalSize validation failed rc=65\n' >&2
+    return 65
+  fi
+
+  if tmp_file=$(mktemp "${DP_BACKUP_INFO_FILE}.tmp.XXXXXX"); then
+    :
+  else
+    status=$?
+    printf 'backup info temporary file creation failed rc=%s\n' "$status" >&2
+    return "$status"
   fi
-  TOTAL_SIZE=$(datasafed stat / | grep TotalSize | awk '{print $2}')
-  echo "{\"totalSize\":\"$TOTAL_SIZE\",\"timeRange\":{\"start\":\"${START_TIME}\",\"end\":\"${STOP_TIME}\"}}" >"${DP_BACKUP_INFO_FILE}"
+
+  if printf '{"totalSize":"%s","timeRange":{"start":"%s","end":"%s"}}\n' \
+    "$total_size" "$start_time" "$stop_time" >"$tmp_file"; then
+    :
+  else
+    status=$?
+    rm -f "$tmp_file" || :
+    printf 'backup info temporary file write failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if mv "$tmp_file" "$DP_BACKUP_INFO_FILE"; then
+    return 0
+  else
+    status=$?
+  fi
+
+  rm -f "$tmp_file" || :
+  printf 'backup info publication failed rc=%s\n' "$status" >&2
+  return "$status"
 }
 
 # if the script exits with a non-zero exit code, touch a file to indicate that the backup failed,
diff --git a/addons/mongodb/dataprotection/datafile-backup.sh b/addons/mongodb/dataprotection/datafile-backup.sh
index 146cc7026c..efb75e8182 100644
--- a/addons/mongodb/dataprotection/datafile-backup.sh
+++ b/addons/mongodb/dataprotection/datafile-backup.sh
@@ -1,9 +1,16 @@
+# shellcheck shell=bash
 set -o pipefail
 export PATH="$PATH:$DP_DATASAFED_BIN_PATH"
 export DATASAFED_BACKEND_BASE_PATH="$DP_BACKUP_BASE_PATH"
 trap handle_exit EXIT
-cd ${DATA_DIR}
-START_TIME=$(get_current_time)
+# shellcheck disable=SC2164
+cd "$DATA_DIR"
+if START_TIME=$(get_current_time); then
+  :
+else
+  status=$?
+  exit "$status"
+fi
 # TODO: flush data and locked write, otherwise data maybe inconsistent
 # NOTE: if files changed during taring, the exit code will be 1 when it ends.
 tar -cvf - ./ | datasafed push -z zstd-fastest - "${DP_BACKUP_NAME}.tar.zst"
diff --git a/addons/mongodb/scripts-ut-spec/backup_info_collector_spec.sh b/addons/mongodb/scripts-ut-spec/backup_info_collector_spec.sh
new file mode 100644
index 0000000000..22c0ad33ee
--- /dev/null
+++ b/addons/mongodb/scripts-ut-spec/backup_info_collector_spec.sh
@@ -0,0 +1,377 @@
+# shellcheck shell=bash disable=SC1091,SC2016
+
+Describe "MongoDB backup info collector contract"
+  setup_backup_info_collector() {
+    test_root=$(mktemp -d "${TMPDIR:-/tmp}/mongodb-backup-info-spec.XXXXXX")
+    fake_bin="$test_root/bin"
+    original_path=$PATH
+    real_mv=$(command -v mv)
+    mkdir -p "$fake_bin"
+
+    cat >"$fake_bin/whereis" <<'SH'
+#!/bin/sh
+printf 'mongosh: %s\n' "$MONGODB_TEST_MONGOSH_BIN"
+SH
+
+    cat >"$fake_bin/mongosh" <<'SH'
+#!/bin/sh
+if [ -n "${MONGODB_TEST_CLIENT_OUTPUT:-}" ]; then
+  printf '%s\n' "$MONGODB_TEST_CLIENT_OUTPUT"
+fi
+exit "${MONGODB_TEST_CLIENT_RC:-0}"
+SH
+
+    cat >"$fake_bin/date" <<'SH'
+#!/bin/sh
+if [ -n "${MONGODB_TEST_DATE_OUTPUT:-}" ]; then
+  printf '%s\n' "$MONGODB_TEST_DATE_OUTPUT"
+fi
+exit "${MONGODB_TEST_DATE_RC:-0}"
+SH
+
+    cat >"$fake_bin/datasafed" <<'SH'
+#!/bin/sh
+case "${1:-}" in
+  stat)
+    if [ -n "${MONGODB_TEST_DATASAFED_OUTPUT:-}" ]; then
+      printf '%s\n' "$MONGODB_TEST_DATASAFED_OUTPUT"
+    fi
+    exit "${MONGODB_TEST_DATASAFED_RC:-0}"
+    ;;
+  push)
+    cat >/dev/null
+    exit 0
+    ;;
+esac
+exit 64
+SH
+
+    cat >"$fake_bin/tar" <<'SH'
+#!/bin/sh
+: >"$MONGODB_TEST_TAR_MARKER"
+exit 0
+SH
+
+    cat >"$fake_bin/mongodump" <<'SH'
+#!/bin/sh
+printf 'archive-data\n'
+exit 0
+SH
+
+    cat >"$fake_bin/mv" <<'SH'
+#!/bin/sh
+if [ -n "${MONGODB_TEST_MV_RC:-}" ]; then
+  exit "$MONGODB_TEST_MV_RC"
+fi
+exec "$MONGODB_TEST_REAL_MV" "$@"
+SH
+
+    chmod +x "$fake_bin/whereis" "$fake_bin/mongosh" \
+      "$fake_bin/date" "$fake_bin/datasafed" "$fake_bin/tar" \
+      "$fake_bin/mongodump" "$fake_bin/mv"
+
+    export PATH="$fake_bin:$original_path"
+    export MONGODB_TEST_MONGOSH_BIN="$fake_bin/mongosh"
+    export MONGODB_TEST_REAL_MV="$real_mv"
+    export DP_DB_USER="backup-user"
+    export DP_DB_PASSWORD="backup-password"
+    export DP_DB_PORT="27017"
+    export DP_DB_HOST="mongodb.example"
+    export DP_DATASAFED_BIN_PATH="$fake_bin"
+    export DP_BACKUP_BASE_PATH="/backup/base"
+    export DP_BACKUP_INFO_FILE="$test_root/backup-info.json"
+    export DATA_DIR="$test_root/data"
+    export MONGODB_TEST_TAR_MARKER="$test_root/tar-called"
+    export MONGODB_TEST_CHILD_VERSION_FILE="$test_root/child-bash-version"
+    export DP_BACKUP_NAME="backup-name"
+    export PARALLEL="1"
+    mkdir -p "$DATA_DIR"
+    unset MONGODB_TEST_CLIENT_OUTPUT
+    unset MONGODB_TEST_CLIENT_RC
+    unset MONGODB_TEST_DATE_OUTPUT
+    unset MONGODB_TEST_DATE_RC
+    unset MONGODB_TEST_DATASAFED_OUTPUT
+    unset MONGODB_TEST_DATASAFED_RC
+    unset MONGODB_TEST_MV_RC
+  }
+  Before "setup_backup_info_collector"
+
+  cleanup_backup_info_collector() {
+    PATH=$original_path
+    export PATH
+    rm -rf "$test_root"
+    unset test_root fake_bin original_path real_mv
+    unset MONGODB_TEST_MONGOSH_BIN
+    unset MONGODB_TEST_REAL_MV
+    unset MONGODB_TEST_CLIENT_OUTPUT
+    unset MONGODB_TEST_CLIENT_RC
+    unset MONGODB_TEST_DATE_OUTPUT
+    unset MONGODB_TEST_DATE_RC
+    unset MONGODB_TEST_DATASAFED_OUTPUT
+    unset MONGODB_TEST_DATASAFED_RC
+    unset MONGODB_TEST_MV_RC
+    unset DP_DB_USER DP_DB_PASSWORD DP_DB_PORT DP_DB_HOST
+    unset DP_DATASAFED_BIN_PATH DP_BACKUP_BASE_PATH DP_BACKUP_INFO_FILE
+    unset DATA_DIR MONGODB_TEST_TAR_MARKER MONGODB_TEST_CHILD_VERSION_FILE
+    unset DP_BACKUP_NAME PARALLEL
+  }
+  After "cleanup_backup_info_collector"
+
+  run_get_current_time() {
+    source ../dataprotection/backup-info-collector.sh
+    get_current_time
+  }
+
+  run_stat_and_report_file() {
+    local status
+
+    source ../dataprotection/backup-info-collector.sh
+    stat_and_save_backup_info \
+      "2026-07-29T00:00:00Z" "2026-07-29T00:05:00Z"
+    status=$?
+    if [ -f "$DP_BACKUP_INFO_FILE" ]; then
+      printf 'file=present\n'
+      cat "$DP_BACKUP_INFO_FILE"
+    else
+      printf 'file=absent\n'
+    fi
+    return "$status"
+  }
+
+  run_datafile_backup_and_report() {
+    local child_version status tar_state info_state exit_marker residue_count
+
+    "$SHELLSPEC_SHELL" -c '
+      printf "%s\n" "$BASH_VERSION" >"$MONGODB_TEST_CHILD_VERSION_FILE"
+      source ../dataprotection/backup-info-collector.sh
+      source ../dataprotection/datafile-backup.sh
+    '
+    status=$?
+    child_version=$(cat "$MONGODB_TEST_CHILD_VERSION_FILE")
+    if [ -f "$MONGODB_TEST_TAR_MARKER" ]; then
+      tar_state=present
+    else
+      tar_state=absent
+    fi
+    if [ -f "$DP_BACKUP_INFO_FILE" ]; then
+      info_state=present
+    else
+      info_state=absent
+    fi
+    if [ -f "${DP_BACKUP_INFO_FILE}.exit" ]; then
+      exit_marker=present
+    else
+      exit_marker=absent
+    fi
+    residue_count=$(find "$test_root" -maxdepth 1 -type f \
+      ! -name backup-info.json ! -name tar-called \
+      ! -name backup-info.json.exit ! -name child-bash-version \
+      | wc -l | tr -d ' ')
+    printf 'tar=%s info=%s marker=%s residue=%s child=%s\n' \
+      "$tar_state" "$info_state" "$exit_marker" "$residue_count" \
+      "$child_version"
+    return "$status"
+  }
+
+  run_empty_time_contract() {
+    local helper_status action_status
+
+    source ../dataprotection/backup-info-collector.sh
+    get_current_time >/dev/null
+    helper_status=$?
+    run_datafile_backup_and_report
+    action_status=$?
+    printf 'helper=%s action=%s\n' "$helper_status" "$action_status"
+    return "$action_status"
+  }
+
+  run_stat_with_existing_destination() {
+    local destination residue_count status
+
+    printf 'previous-metadata\n' >"$DP_BACKUP_INFO_FILE"
+    source ../dataprotection/backup-info-collector.sh
+    stat_and_save_backup_info \
+      "2026-07-29T00:00:00Z" "2026-07-29T00:05:00Z"
+    status=$?
+    destination=$(cat "$DP_BACKUP_INFO_FILE")
+    residue_count=$(find "$test_root" -maxdepth 1 -type f \
+      ! -name backup-info.json ! -name tar-called | wc -l | tr -d ' ')
+    printf 'destination=%s residue=%s\n' "$destination" "$residue_count"
+    return "$status"
+  }
+
+  run_mongodump_publication_failure() {
+    local child_version destination exit_marker residue_count status
+
+    printf 'previous-metadata\n' >"$DP_BACKUP_INFO_FILE"
+    "$SHELLSPEC_SHELL" -c '
+      printf "%s\n" "$BASH_VERSION" >"$MONGODB_TEST_CHILD_VERSION_FILE"
+      source ../dataprotection/backup-info-collector.sh
+      source ../dataprotection/mongodump-backup.sh
+    '
+    status=$?
+    child_version=$(cat "$MONGODB_TEST_CHILD_VERSION_FILE")
+    destination=$(cat "$DP_BACKUP_INFO_FILE")
+    if [ -f "${DP_BACKUP_INFO_FILE}.exit" ]; then
+      exit_marker=present
+    else
+      exit_marker=absent
+    fi
+    residue_count=$(find "$test_root" -maxdepth 1 -type f \
+      ! -name backup-info.json ! -name backup-info.json.exit \
+      ! -name tar-called ! -name child-bash-version | wc -l | tr -d ' ')
+    printf 'destination=%s marker=%s residue=%s child=%s\n' \
+      "$destination" "$exit_marker" "$residue_count" "$child_version"
+    return "$status"
+  }
+
+  It "preserves the MongoDB client failure instead of fabricating a timestamp"
+    export MONGODB_TEST_CLIENT_RC=17
+    export MONGODB_TEST_DATE_OUTPUT="2026-07-29T00:00:00Z"
+
+    When call run_get_current_time
+
+    The status should equal 17
+    The output should be blank
+    The stderr should equal "backup info timestamp client failed rc=17"
+  End
+
+  It "fails when the client timestamp cannot be converted"
+    export MONGODB_TEST_CLIENT_OUTPUT="not-an-epoch"
+    export MONGODB_TEST_DATE_RC=11
+
+    When call run_get_current_time
+
+    The status should equal 11
+    The output should be blank
+    The stderr should equal "backup info timestamp conversion failed rc=11"
+  End
+
+  It "classifies empty successful MongoDB output before the datafile backup"
+    export MONGODB_TEST_DATE_OUTPUT="2026-07-29T00:00:00Z"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+
+    When call run_empty_time_contract
+
+    The status should equal 1
+    The line 1 of output should equal "failed with exit code 65"
+    The line 2 of output should equal "tar=absent info=absent marker=present residue=0 child=$BASH_VERSION"
+    The line 3 of output should equal "helper=65 action=1"
+    The stderr should equal "backup info timestamp client returned empty output rc=65
+backup info timestamp client returned empty output rc=65"
+  End
+
+  It "classifies empty successful date output before the datafile backup"
+    export MONGODB_TEST_CLIENT_OUTPUT="1753747200"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+
+    When call run_empty_time_contract
+
+    The status should equal 1
+    The line 1 of output should equal "failed with exit code 65"
+    The line 2 of output should equal "tar=absent info=absent marker=present residue=0 child=$BASH_VERSION"
+    The line 3 of output should equal "helper=65 action=1"
+    The stderr should equal "backup info timestamp conversion returned empty output rc=65
+backup info timestamp conversion returned empty output rc=65"
+  End
+
+  It "preserves datasafed failure and does not write backup metadata"
+    export MONGODB_TEST_DATASAFED_RC=23
+
+    When call run_stat_and_report_file
+
+    The status should equal 23
+    The output should equal "file=absent"
+    The stderr should equal "backup info datasafed stat failed rc=23"
+  End
+
+  It "rejects a successful datasafed response without TotalSize"
+    export MONGODB_TEST_DATASAFED_OUTPUT="Files 4"
+
+    When call run_stat_and_report_file
+
+    The status should be failure
+    The output should equal "file=absent"
+    The stderr should equal "backup info TotalSize validation failed rc=65"
+  End
+
+  It "rejects an empty TotalSize value without replacing existing metadata"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize:"
+
+    When call run_stat_with_existing_destination
+
+    The status should equal 65
+    The output should equal "destination=previous-metadata residue=0"
+    The stderr should equal "backup info TotalSize validation failed rc=65"
+  End
+
+  It "rejects duplicate TotalSize values without replacing existing metadata"
+    MONGODB_TEST_DATASAFED_OUTPUT='TotalSize: 42
+TotalSize: 84'
+    export MONGODB_TEST_DATASAFED_OUTPUT
+
+    When call run_stat_with_existing_destination
+
+    The status should equal 65
+    The output should equal "destination=previous-metadata residue=0"
+    The stderr should equal "backup info TotalSize validation failed rc=65"
+  End
+
+  It "rejects a JSON-unsafe TotalSize value without replacing existing metadata"
+    export MONGODB_TEST_DATASAFED_OUTPUT='TotalSize: "'
+
+    When call run_stat_with_existing_destination
+
+    The status should equal 65
+    The output should equal "destination=previous-metadata residue=0"
+    The stderr should equal "backup info TotalSize validation failed rc=65"
+  End
+
+  It "writes exact metadata for a valid datasafed TotalSize response"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+
+    When call run_stat_and_report_file
+
+    The status should be success
+    The line 1 of output should equal "file=present"
+    The line 2 of output should equal '{"totalSize":"42","timeRange":{"start":"2026-07-29T00:00:00Z","end":"2026-07-29T00:05:00Z"}}'
+  End
+
+  It "stops the datafile backup before tar when the start timestamp fails"
+    export MONGODB_TEST_CLIENT_RC=17
+    export MONGODB_TEST_DATE_OUTPUT="2026-07-29T00:00:00Z"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+
+    When call run_datafile_backup_and_report
+
+    The status should equal 1
+    The line 1 of output should equal "failed with exit code 17"
+    The line 2 of output should equal "tar=absent info=absent marker=present residue=0 child=$BASH_VERSION"
+    The stderr should equal "backup info timestamp client failed rc=17"
+  End
+
+  It "preserves existing metadata and removes temporary output when publication fails"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+    export MONGODB_TEST_MV_RC=29
+
+    When call run_stat_with_existing_destination
+
+    The status should equal 29
+    The output should equal "destination=previous-metadata residue=0"
+    The stderr should equal "backup info publication failed rc=29"
+  End
+
+  It "cleans failed publication under mongodump errexit and records action failure"
+    export MONGODB_TEST_CLIENT_OUTPUT="1753747200"
+    export MONGODB_TEST_DATE_OUTPUT="2026-07-29T00:00:00Z"
+    export MONGODB_TEST_DATASAFED_OUTPUT="TotalSize: 42"
+    export MONGODB_TEST_MV_RC=29
+
+    When call run_mongodump_publication_failure
+
+    The status should equal 1
+    The line 1 of output should equal "failed with exit code 29"
+    The line 2 of output should equal "destination=previous-metadata marker=present residue=0 child=$BASH_VERSION"
+    The stderr should equal "backup info publication failed rc=29"
+  End
+End