# Data model for a multi-tenant tagging/commenting system **URL:** \ **Category:** Elasticsearch\ **Created:** [August 11, 2016, 4:17pm UTC](https://discuss.elastic.co/t/data-model-for-a-multi-tenant-tagging-commenting-system/57837 "2016-08-11T16:17:10Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![mscifo](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mscifo/32/11333_2.png) [@mscifo](https://discuss.elastic.co/u/mscifo)\ **Post date:** [August 11, 2016, 4:17pm UTC](https://discuss.elastic.co/t/data-model-for-a-multi-tenant-tagging-commenting-system/57837/1 "2016-08-11T16:17:10Z")
I have a need to add multi-tenant tagging and commenting support to a system whose primary datastore is ES 2.3. There are currently around 5 million public documents in a single index spread across 5 shards in a 2 node cluster. New documents are added every minute, averaging about 2500 per day. Documents themselves are never updated/deleted. Requirements: - each tenant must be able to add tags and comments to each document that are only viewable by them - admins must be able to add global tags and comments to each document that are viewable by all tenants and inlined with the tenant's tags and comments - comments will not be threaded, only chronological - queries (described below) must also support inclusion of conditions against the root document fields such as title, author, creation\_time, etc - must maintain fast query response times - don't allow any one tenant to affect performance of another - don't disrupt ability to easily horizontally scale Must have queries: - get global and tenant specific tags for all documents in as few queries as possible for list page (paged via infinite scroll) - get all global and tenant specific tags for a single document on detail page - get paged global and tenant specific comments for a single document ordered by timestamp - ability to query documents based on [non]existence of global and tenant specific tags - ability to query documents that don't have any global or tenant specific tags - ability to query documents that don't have any global or tenant specific comments - ability to query documents that have a global or tenant specific comment within past X timeframe - ability to add one or many global or tenant specific tags to a single or list of bulk selected documents with as few queries as possible - ability to add a global or tenant specific comment to a single document - ability to autocomplete search amongst all of a specific tenants tags Nice to have queries: - ability to query list of most recent tags amongst all tenants or a specific tenant - ability to query list of most used tags (and document count per) amongst all tenants or a specific tenant within a specified time period (histogram) - ability to query a list of most recent comments amongst all tenants or a specific tenant - ability to query number of tags/comments applied amongst all tenants or a specific tenant within a specified time period (histogram) - ability to bulk delete tags across one or all tenants Potential options: - ES Inner Objects - concerns include one tenant affecting performance for others by adding thousands of tags/comments, inability to retrieve document with only a specific tenant's (and global) tags/comments instead of all of them and filtering them out via code - ES Nested Documents - concerns include adding new tags/comments forces a reindex of the entire root document, which could take a lot of time/resources if many tags/comments exist for many tenants - ES Parent/Child Types - concerns include memory overhead, potential difficult with some of the nice to have queries identified above - Denormalization (store tags/comments in another datastore such as MongoDB or Postgres) - concerns include having to query two data stores and merge results in code which could greatly affect performance, especially for list view where I need all tags for all displayed documents I would appreciate any architectural insights or recommendations based on my needs. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:28pm UTC](https://discuss.elastic.co/t/data-model-for-a-multi-tenant-tagging-commenting-system/57837/2 "2017-07-05T22:28:19Z")
Closed on July 5, 2017, 10:28pm UTC