From 35a9a1dec44c5f28bb5c43b1c3dcf6803ca1a328 Mon Sep 17 00:00:00 2001 From: Liuxiaozhen12 Date: Thu, 1 Jul 2021 16:22:04 +0800 Subject: [PATCH 1/2] Clarify tidb lightning backend description --- tidb-lightning/deploy-tidb-lightning.md | 3 +-- tidb-lightning/tidb-lightning-backends.md | 1 + 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tidb-lightning/deploy-tidb-lightning.md b/tidb-lightning/deploy-tidb-lightning.md index b504d25fce02e..937e30e5882f9 100644 --- a/tidb-lightning/deploy-tidb-lightning.md +++ b/tidb-lightning/deploy-tidb-lightning.md @@ -8,13 +8,12 @@ aliases: ['/docs/stable/tidb-lightning/deploy-tidb-lightning/','/docs/v4.0/tidb- This document describes the hardware requirements of TiDB Lightning using the Local-backend, and how to deploy it using TiDB Ansible or manually. -If you do not want the TiDB services to be impacted, read [TiDB Lightning TiDB-backend](/tidb-lightning/tidb-lightning-backends.md#tidb-lightning-tidb-backend) for the changes to the deployment steps. +If Local-backend is used for data import, during the import process, **the cluster cannot provide normal services**. If you do not want the TiDB services to be impacted, read [TiDB Lightning TiDB-backend](/tidb-lightning/tidb-lightning-backends.md#tidb-lightning-tidb-backend) for the changes to the deployment steps. ## Notes Before starting TiDB Lightning, note that: -- During the import process, the cluster cannot provide normal services. - If `tidb-lightning` crashes, the cluster is left in "import mode". Forgetting to switch back to "normal mode" can lead to a high amount of uncompacted data on the TiKV cluster, and cause abnormally high CPU usage and stall. You can manually switch the cluster back to "normal mode" via the `tidb-lightning-ctl` tool: ```sh diff --git a/tidb-lightning/tidb-lightning-backends.md b/tidb-lightning/tidb-lightning-backends.md index 30b0689120f6e..e8c6b48917b57 100644 --- a/tidb-lightning/tidb-lightning-backends.md +++ b/tidb-lightning/tidb-lightning-backends.md @@ -29,6 +29,7 @@ The **TiDB-backend**: `tidb-lightning` first encodes these data into SQL `INSERT | Target tables | Must be empty | Must be empty | Can be populated | | Additional component required | No | `tikv-importer` | No | | TiDB versions supported | >= v4.0.0 | All | All | +| TiDB services impacted | Yes | Yes | No | ## How to choose the backend modes From bd92a173231264d6919b8e88c508c7e06a3ef3bb Mon Sep 17 00:00:00 2001 From: TomShawn <41534398+TomShawn@users.noreply.github.com> Date: Thu, 1 Jul 2021 19:11:33 +0800 Subject: [PATCH 2/2] Update tidb-lightning/deploy-tidb-lightning.md --- tidb-lightning/deploy-tidb-lightning.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tidb-lightning/deploy-tidb-lightning.md b/tidb-lightning/deploy-tidb-lightning.md index 937e30e5882f9..d3629a12badb7 100644 --- a/tidb-lightning/deploy-tidb-lightning.md +++ b/tidb-lightning/deploy-tidb-lightning.md @@ -8,7 +8,7 @@ aliases: ['/docs/stable/tidb-lightning/deploy-tidb-lightning/','/docs/v4.0/tidb- This document describes the hardware requirements of TiDB Lightning using the Local-backend, and how to deploy it using TiDB Ansible or manually. -If Local-backend is used for data import, during the import process, **the cluster cannot provide normal services**. If you do not want the TiDB services to be impacted, read [TiDB Lightning TiDB-backend](/tidb-lightning/tidb-lightning-backends.md#tidb-lightning-tidb-backend) for the changes to the deployment steps. +If Local-backend is used for data import, during the import process, **the cluster cannot provide services**. If you do not want the TiDB services to be impacted, perform the data import according to [TiDB Lightning TiDB-backend](/tidb-lightning/tidb-lightning-backends.md#tidb-lightning-tidb-backend). ## Notes