From ad718f02a68823c117fc83311a9306e092035d53 Mon Sep 17 00:00:00 2001 From: toutdesuite Date: Thu, 9 Apr 2020 11:24:28 +0800 Subject: [PATCH 1/5] add faq.md --- TOC.md | 1 + reference/tiflash/faq.md | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) create mode 100644 reference/tiflash/faq.md diff --git a/TOC.md b/TOC.md index 4d3b48547e1d1..9905356035ed6 100644 --- a/TOC.md +++ b/TOC.md @@ -307,6 +307,7 @@ - [Overview](/reference/tiflash/overview.md) - [Deploy a TiFlash Cluster](/reference/tiflash/deploy.md) - [Use TiFlash](/reference/tiflash/use-tiflash.md) + - [FAQ](/reference/tiflash/faq.md) + TiDB Binlog - [Overview](/reference/tidb-binlog/overview.md) - [Deploy](/reference/tidb-binlog/deploy.md) diff --git a/reference/tiflash/faq.md b/reference/tiflash/faq.md new file mode 100644 index 0000000000000..348e35fff0ffe --- /dev/null +++ b/reference/tiflash/faq.md @@ -0,0 +1,29 @@ +--- +title: TiFlash FAQ +summary: Learn the Frequently Asked Questions and the solutions about TiDB. +category: faq +--- + +# TiFlash FAQ + +This document lists the Frequently Asked Questions and the solutions about TiDB. + +## Does TiFlash support direct writes? + +Currently, TiFlash does not support direct writes. You can only write to TiKV, and then replicate to TiFlash. + +## How can I estimate the storage resources if I want to add TiFlash to an existing cluster? + +You can evaluate which tables might require acceleration. The size a single replica of these tables data is roughly equal to the storage resources required by two replicas of TiFlash. Note that you need to take into account the free space required. + +## How do TiFlash data be highly available? + +TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV is available, TiFlash can perform data restore using these Regions. + +## How many replicas does TiFlash recommend to set up? + +If you need highly available TiFlash service (rather than highly available data), it is recommended to set up two replicas for TiFlash. If the TiKV replicas are allowed to provide service when TiFlash loses nodes, you can set up a single replica. + +## Should I use TiSpark or TiDB server for a query? + +It is recommended to use TiDB server if you query single table collection or you use the filtering query, because TiDB server shows better performance on the columnar storage. It is recommended to use TiSpark if you query table joins. From c0a88c8bfd8fb2d4b2c58c660fc71b66bf948f29 Mon Sep 17 00:00:00 2001 From: toutdesuite Date: Thu, 9 Apr 2020 20:42:15 +0800 Subject: [PATCH 2/5] address comment --- reference/tiflash/faq.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/reference/tiflash/faq.md b/reference/tiflash/faq.md index 348e35fff0ffe..4d125cdc613e9 100644 --- a/reference/tiflash/faq.md +++ b/reference/tiflash/faq.md @@ -26,4 +26,4 @@ If you need highly available TiFlash service (rather than highly available data) ## Should I use TiSpark or TiDB server for a query? -It is recommended to use TiDB server if you query single table collection or you use the filtering query, because TiDB server shows better performance on the columnar storage. It is recommended to use TiSpark if you query table joins. +It is recommended to use TiDB server if you query a single table with filtering and aggregation, because TiDB server shows better performance on the columnar storage. It is recommended to use TiSpark if you query table joins. From 15255aeeacea48fb0886a4f2893c3e8eb09c98a4 Mon Sep 17 00:00:00 2001 From: toutdesuite Date: Fri, 10 Apr 2020 11:21:06 +0800 Subject: [PATCH 3/5] small edit --- reference/tiflash/faq.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/reference/tiflash/faq.md b/reference/tiflash/faq.md index 4d125cdc613e9..075acaf6ef717 100644 --- a/reference/tiflash/faq.md +++ b/reference/tiflash/faq.md @@ -18,7 +18,7 @@ You can evaluate which tables might require acceleration. The size a single repl ## How do TiFlash data be highly available? -TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV is available, TiFlash can perform data restore using these Regions. +TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV are available, TiFlash can perform data restore using these Regions. ## How many replicas does TiFlash recommend to set up? From dfc30011467586584433f947f952637ec689143c Mon Sep 17 00:00:00 2001 From: toutdesuite Date: Fri, 10 Apr 2020 14:14:37 +0800 Subject: [PATCH 4/5] address comments --- reference/tiflash/faq.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/reference/tiflash/faq.md b/reference/tiflash/faq.md index 075acaf6ef717..217c98f857cdf 100644 --- a/reference/tiflash/faq.md +++ b/reference/tiflash/faq.md @@ -1,29 +1,29 @@ --- title: TiFlash FAQ -summary: Learn the Frequently Asked Questions and the solutions about TiDB. +summary: Learn the frequently asked questions (FAQs) and answers about TiFlash. category: faq --- # TiFlash FAQ -This document lists the Frequently Asked Questions and the solutions about TiDB. +This document lists the frequently asked questions (FAQs) and answers about TiFlash. ## Does TiFlash support direct writes? -Currently, TiFlash does not support direct writes. You can only write to TiKV, and then replicate to TiFlash. +Currently, TiFlash does not support direct writes. You can only write data to TiKV, and then replicate the data to TiFlash. ## How can I estimate the storage resources if I want to add TiFlash to an existing cluster? -You can evaluate which tables might require acceleration. The size a single replica of these tables data is roughly equal to the storage resources required by two replicas of TiFlash. Note that you need to take into account the free space required. +You can evaluate which tables might require acceleration. The size of a single replica of these tables data is roughly equal to the storage resources required by two replicas of TiFlash. Note that you need to take into account the free space required. -## How do TiFlash data be highly available? +## How can data in TiFlash be highly available? -TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV are available, TiFlash can perform data restore using these Regions. +TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV are available, TiFlash can restore data from these Regions. ## How many replicas does TiFlash recommend to set up? -If you need highly available TiFlash service (rather than highly available data), it is recommended to set up two replicas for TiFlash. If the TiKV replicas are allowed to provide service when TiFlash loses nodes, you can set up a single replica. +If you need highly available TiFlash service (rather than highly available data), it is recommended to set up two replicas for TiFlash. If the TiKV replicas are allowed to resume the TiFlash service when TiFlash loses nodes, you can set up a single TiFlash replica. ## Should I use TiSpark or TiDB server for a query? -It is recommended to use TiDB server if you query a single table with filtering and aggregation, because TiDB server shows better performance on the columnar storage. It is recommended to use TiSpark if you query table joins. +It is recommended to use TiDB server if you query a single table mainly using filtering and aggregation, because the TiDB server has better performance on the columnar storage. It is recommended to use TiSpark if you query a table mainly using joins. From 75640b54b0214131c24f767d647624c100c833bd Mon Sep 17 00:00:00 2001 From: TomShawn <41534398+TomShawn@users.noreply.github.com> Date: Fri, 10 Apr 2020 15:47:46 +0800 Subject: [PATCH 5/5] update a sentence --- reference/tiflash/faq.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/reference/tiflash/faq.md b/reference/tiflash/faq.md index 217c98f857cdf..f595677ea79c8 100644 --- a/reference/tiflash/faq.md +++ b/reference/tiflash/faq.md @@ -22,7 +22,7 @@ TiFlash restores data through TiKV. As long as the corresponding Regions in TiKV ## How many replicas does TiFlash recommend to set up? -If you need highly available TiFlash service (rather than highly available data), it is recommended to set up two replicas for TiFlash. If the TiKV replicas are allowed to resume the TiFlash service when TiFlash loses nodes, you can set up a single TiFlash replica. +If you need highly available TiFlash services (rather than highly available data), it is recommended to set up two replicas for TiFlash. If you allow TiKV replicas to provide analytical services when TiFlash is down, you can set up a single TiFlash replica. ## Should I use TiSpark or TiDB server for a query?