List View performance degradation

If we rapidly add lots of content under the same node the list view starts to slow down to the point where some pages will not load and an SQL timeout error will be thrown.

Umbraco version 8

I am seeing this issue on Umbraco version: 8.2.1 and 8.3.0 (didn’t test any other version). Both Cloud and On Premise have this issue.

Reproduction

Bug summary

List View slows down once we start to push lots of data under the same node. I’ talking about 500+ items (which is technically not a lot of data). Each page starts to load a bit slower.

• 1st page - 180ms
• 5th page - 245ms
• 10th page - 321ms
• 30th page - 1200ms

It looks like a linear progression.

Sometimes the issue resolves itself and load times start becoming the same for each of the page - 300ms. If I load more data it will start “lagging” again.

I’ve used an SQL Profiler and it seems that the query which actually retrieves data slows down depending on which page we retrieve. If I try to run the query separately it works fast (doesn’t go into seconds - only milliseconds). It feels like there is something parallel going on when we request a page of the list to load which slows down this specific query.

This is an example of the query:

exec sp_executesql N'SELECT [umbracoDocument].[nodeId] AS [NodeId], [umbracoDocument].[published] AS [Published], [umbracoDocument].[edited] AS [Edited] , [umbracoContent].[nodeId] AS [ContentDto__NodeId], 
[umbracoContent].[contentTypeId] AS [ContentDto__ContentTypeId] , [umbracoNode].[id] AS [ContentDto__NodeDto__NodeId], [umbracoNode].[uniqueId] AS [ContentDto__NodeDto__UniqueId], [umbracoNode].[parentId] AS 
[ContentDto__NodeDto__ParentId], [umbracoNode].[level] AS [ContentDto__NodeDto__Level], [umbracoNode].[path] AS [ContentDto__NodeDto__Path], [umbracoNode].[sortOrder] AS [ContentDto__NodeDto__SortOrder], 
[umbracoNode].[trashed] AS [ContentDto__NodeDto__Trashed], [umbracoNode].[nodeUser] AS [ContentDto__NodeDto__UserId], [umbracoNode].[text] AS [ContentDto__NodeDto__Text], [umbracoNode].[nodeObjectType] AS 
[ContentDto__NodeDto__NodeObjectType], [umbracoNode].[createDate] AS [ContentDto__NodeDto__CreateDate] , [umbracoDocumentVersion].[id] AS [DocumentVersionDto__Id], [umbracoDocumentVersion].[templateId] AS 
[DocumentVersionDto__TemplateId], [umbracoDocumentVersion].[published] AS [DocumentVersionDto__Published] , [umbracoContentVersion].[id] AS [DocumentVersionDto__ContentVersionDto__Id], 
[umbracoContentVersion].[nodeId] AS [DocumentVersionDto__ContentVersionDto__NodeId], [umbracoContentVersion].[versionDate] AS [DocumentVersionDto__ContentVersionDto__VersionDate], [umbracoContentVersion].[userId] 
AS [DocumentVersionDto__ContentVersionDto__UserId], [umbracoContentVersion].[current] AS [DocumentVersionDto__ContentVersionDto__Current], [umbracoContentVersion].[text] AS [DocumentVersionDto__ContentVersionDto__Text] , [pdv].[id] AS [PublishedVersionDto__Id], [pdv].[templateId] AS [PublishedVersionDto__TemplateId], [pdv].[published] AS [PublishedVersionDto__Published] , [pcv].[id] AS [PublishedVersionDto__ContentVersionDto__Id], [pcv].[nodeId] AS [PublishedVersionDto__ContentVersionDto__NodeId], [pcv].[versionDate] AS [PublishedVersionDto__ContentVersionDto__VersionDate], [pcv].[userId] AS [PublishedVersionDto__ContentVersionDto__UserId], [pcv].[current] AS [PublishedVersionDto__ContentVersionDto__Current], [pcv].[text] AS [PublishedVersionDto__ContentVersionDto__Text] , COALESCE([ccv].[name],[umbracoNode].[text]) AS variantName FROM [umbracoDocument] INNER JOIN [umbracoContent] ON [umbracoDocument].[nodeId] = [umbracoContent].[nodeId] INNER JOIN [umbracoNode] ON [umbracoContent].[nodeId] = [umbracoNode].[id] INNER JOIN [umbracoContentVersion] ON ([umbracoDocument].[nodeId] = [umbracoContentVersion].[nodeId]) INNER JOIN [umbracoDocumentVersion] ON ([umbracoContentVersion].[id] = [umbracoDocumentVersion].[id]) LEFT JOIN [umbracoContentVersion] [pcv] INNER JOIN [umbracoDocumentVersion] [pdv] ON (([pcv].[id] = [pdv].[id]) AND [pdv].[published] = @0) ON ([umbracoDocument].[nodeId] = [pcv].[nodeId]) LEFT JOIN [umbracoContentVersionCultureVariation] [ccv] INNER JOIN [umbracoLanguage] [lang] ON (([ccv].[languageId] = [lang].[id]) AND ([lang].[languageISOCode] = @1)) ON ([umbracoContentVersion].[id] = [ccv].[versionId]) WHERE (([umbracoNode].[nodeObjectType] = @2)) AND ([umbracoContentVersion].[current] = @3) AND (([umbracoNode].[parentId] = @4)) ORDER BY [DocumentVersionDto__ContentVersionDto__VersionDate] DESC , [ContentDto__NodeDto__NodeId]
OFFSET @5 ROWS FETCH NEXT @6 ROWS ONLY',N'@0 int,@1 nvarchar(4000),@2 uniqueidentifier,@3 int,@4 int,@5 bigint,@6 bigint',@0=1,@1=N'en-US',@2='C66BA18E-EAF3-4CFF-8A22-41B16D66A972',@3=1,@4=1053,@5=11400,@6=100

I’ve also tried rebuilding some indexes (the most fragmented ones). That seemed to have helped improve performance however the underlying issue of page retrieval speed still persisted.

Steps to reproduce

Create 2 document types (parent and child) and enable the list view on the parent. Use any way of inserting lots of data into the list

• for loop in the API using IContentService
• run a JS loop in browser and use umbraco/backoffice/UmbracoApi/Content/PostSave Add at least 500 items (preferably 2000 items). Try navigating the list while opening the network tab and recording times to finish GetChildren calls. Go to first page, middle page, last page.

JS code to insert many items into the list (needs to be updated with correct values and can be run from any backoffice page):

function uuidv4() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

for (var i = 0; i < 500; i++)
{
	var uuid = uuidv4();
	var data = new FormData();
	data.append('contentItem', `{"id":0,"contentTypeAlias":"item","parentId":1136,"action":"publishNew","variants":[{"name":"${uuid}","properties":[{"id":0,"alias":"text","value":"${uuid}"}],"culture":null,"publish":true,"save":true,"releaseDate":null,"expireDate":null}],"expireDate":null,"releaseDate":null,"templateAlias":null}`);
	
	var result = await fetch('https://mvc-asa-solutionlab-net.s1.umbraco.io/umbraco/backoffice/UmbracoApi/Content/PostSave', { method: 'post', body: data } );
	console.log(`Adding '${i}' item. Status: '${result.status}'`);
}

Expected result

Each page have a similar load time as the SQL Query should differ only by offset.

Actual result

The first page loads fast. Middle page loads a lot slower (depends on the number of pages) Last page load really slow or doesn’t load at all (throws SQL Timeout exception)

---

This item has been added to our backlog AB#4023

[asmailov]

This will most likely be an index we’ll be adding. You can do this now to see how this affects your list view performance and please let me know if this resolves the issue for you

CREATE NONCLUSTERED INDEX [IX_umbracoContentVersion_NodeId] ON [dbo].[umbracoContentVersion]
(
	[nodeId] ASC,
	[current] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO

There’s some other optimizations were doing too but this hopefully should be the main culprit

Thanks! The index exponentially speeds up the load times! 👍

[Shazwazza]

Have submitted a PR here https://github.com/umbraco/Umbraco-CMS/pull/7316