awsdocs / amazon-elasticache-docs

The open source version of the Amazon ElastiCache User Guide. You can submit feedback and requests for changes by submitting issues in this repo or by making proposed changes and submitting a pull request.

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amazon-elasticache-docs's Issues

Doc page for Outposts doesn't indicate ElastiCache back end EBS consumption

Referring to this page: https://github.com/awsdocs/amazon-elasticache-docs/blob/master/doc_source/redis/ElastiCache-Outposts.md

On Outposts, EBS capacity is a constrained resource. ElastiCache abstracts its EBS usage from users in the region but can't do the same on Outposts due to this constraint. This documentation page needs to tell customers how much EBS capacity ElastiCache nodes of each size consume so that customers can plan their Outpost cluster deployments without getting unanticipated EBS capacity exceptions.

Document what "enhanced IO" means

At https://github.com/awsdocs/amazon-elasticache-docs/blob/master/doc_source/redis/VersionManagement.md, it says:

If you upgrade to engine version 5.0.3 or higher and the number of vCPUs is at least 4, enhanced IO triggers and you can expect to see increased EngineCPUUtilization and CPUUtilization.

But it doesn't explain what "enhanced IO" means, or why you would want this. I found this blog post, which discusses "enhanced I/O handling": https://aws.amazon.com/blogs/database/boosting-application-performance-and-reducing-costs-with-amazon-elasticache-for-redis/

Assuming that blog post is talking about the same thing, I'd be nice to incorporate that information into the documentation.

Missing wget when performing yum install

Missing wget would cause the instruction fail to build the redis-cli for amazon linux 2

Use Primary instead of Primary??

For write activity, we recommend that your applications connect to the primary endpoint instead of connecting directly to the primary

What is meant here? I'm assuming one of it isn't primary.

https://github.com/awsdocs/amazon-elasticache-docs/blob/master/doc_source/redis/Endpoints.md

Content/Title/Url mismatch on page: BestPractices.AOF.md

What document is this regarding?

https://github.com/awsdocs/amazon-elasticache-docs/blob/master/doc_source/redis/BestPractices.AOF.md

Observed issue:

The following three elements of the page are all seemingly unrelated to each other:

• page title: "Mitigating Out-of-Disk-Space Issues When Using Redis AOF"
• document url: "BestPractices.AOF"
• narrative content

The narrative content of this page, below the title, neither describes or makes mention of "disk space", nor does it contain any content regarding "mitigation" or best practices.

add separate examples for cluster enabled/disabled

You should add better/separate AWS CLI examples for describe-cache-clusters and describe-replication-groups for differentiating cluster mode disabled and enabled. The examples only describe cluster mode disabled, what about cluster mode enabled, how do you find the primary replica node endpoints?

And, why aren't there separate DNS names for write masters and slaves, some times you don't want reads coming from read slaves.

Unable to configure ElastiCache for outsude access

I tried to use this guide to get access to my ElastiCache cluster via the VPN:
https://github.com/awsdocs/amazon-elasticache-docs/blob/master/doc_source/redis/accessing-elasticache.md

And after creating all the certs and establishing VPN connection I was able to access the redis DB via telnet.

However I need to be able to access internes as well because my application loads it's configuration thru different resources.

Currently when I'm connected with VPN I do not have any internet access at all.

Guide says that to enable internet access i need to "Target VPC Subnet ID: Select one of the associated subnets with access to the Internet."
But it doesn't really explain how to do this.

When first created(following the guide) the only subnet that belongs to that VPC takes the entire block of IP addresses so I cannot add an additional subnet and I also cannot associate a different VPC with the other subnet.
I also wasn't able to split this Elasticache subnet into two but maybe I'm not doing something right.

Would be nice to show an example of how this can be achieved.

Thanks!

Redis 6

Would you know when Redis 6 will be added? Can we add an estimated timeframe to the documentation?

Latest Supported Version of Memcached and Redis on FAQ

Elasticache FAQ https://aws.amazon.com/elasticache/faqs/ mention

• Memcached 1.5.10 as latest supported. Currently Memcached 1.5.16 already supported by ElastiCache.
• Redis 5.0.3 as latest supported. Currently Redis 5.0.4 is already supported by ElastiCache.

Outdated statement about resharding with cluster mode enabled

In redis/CacheNodes.NodeGroups.md, there's the following statement, which caused us some confusion:

When you create a Redis (cluster mode enabled) cluster, you specify from 1 to 15 shards. Currently, however, unlike Redis (cluster mode disabled) clusters, once a Redis (cluster mode enabled) cluster is created, its structure cannot be altered in any way; you cannot add or delete nodes or shards. If you need to add or delete nodes, or change node types, you must create the cluster anew.

Is this still correct since it seems online resharding is now supported for Redis clusters, or am I misunderstanding the context here?