Repository: tikv/tikv
File: metrics/grafana/tikv_details.dashboard.py (Python)

Code before:
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="95%",
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_avg(
                            "tikv_engine_write_wal_time_micro_seconds",
                            label_selectors=[
                                'db="$db"',
                                'type="write_wal_micros_average"',
                            ],
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="avg",
                        additional_groupby=True,
                    ),
                ],
            ),
        ]
    )
    layout.row(
        [
            graph_panel(
                title="Compaction operations",
                description="The count of compaction and flush operations",
                yaxes=yaxes(left_format=UNITS.OPS_PER_SEC, right_format=UNITS.SHORT),
                targets=[
                    target(
                        expr=expr_sum_rate(
                            "tikv_engine_event_total",
                            label_selectors=[
                                'db="$db"',
                            ],
                            by_labels=["type"],
                        ),
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_sum(
                            "tikv_engine_num_running_compactions",
                            label_selectors=[
                                'db="$db"',
                            ],
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="running-compactions",
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_sum(

Review comment (suggestion):
maybe this helps distinguish the two metrics
```suggestion
                description="The rate of completed compaction and flush operations (left axis) and the count of running operations (right axis).",
```

Code after:
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="95%",
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_avg(
                            "tikv_engine_write_wal_time_micro_seconds",
                            label_selectors=[
                                'db="$db"',
                                'type="write_wal_micros_average"',
                            ],
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="avg",
                        additional_groupby=True,
                    ),
                ],
            ),
        ]
    )
    layout.row(
        [
            graph_panel(
                title="Compaction operations",
                description="The rate of completed compaction and flush operations (left axis) and the count of running operations (right axis).",
                yaxes=yaxes(left_format=UNITS.OPS_PER_SEC, right_format=UNITS.SHORT),
                targets=[
                    target(
                        expr=expr_sum_rate(
                            "tikv_engine_event_total",
                            label_selectors=[
                                'db="$db"',
                            ],
                            by_labels=["type"],
                        ),
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_sum(
                            "tikv_engine_num_running_compactions",
                            label_selectors=[
                                'db="$db"',
                            ],
                            by_labels=[],  # override default by instance.
                        ),
                        legend_format="running-compactions",
                        additional_groupby=True,
                    ),
                    target(
                        expr=expr_sum(