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Don't just learn the cloud—BYTE it!
Byte the Cloud is your go-to, on-the-go, podcast for mastering AWS, Azure, and Google Cloud certifications and exam prep!
Chris 0:00
All right, let's do a deep dive into Amazon Elasticache.
Kelly 0:02
Okay, sounds good. You
Chris 0:03
know, as mid level cloud engineers, I'm sure we've all dealt with those performance issues, right? Oh, yeah,
Kelly 0:07
for sure, making applications fast is always a challenge, definitely,
Chris 0:11
and that's where Elasticache comes in. It's this managed caching service that can really make your app perform better, yeah, and more scalable too.
Kelly 0:20
It's kind of like adding a turbocharger to your data. Okay,
Chris 0:23
I like that. How so well, instead
Kelly 0:24
of hitting your database constantly, Elasticache keeps all the frequently used data in memory. Ah, I see. So it means faster access and less strain on your database, which is a good thing. Yeah, that
Chris 0:37
makes sense. So it's like a dedicated express lane for your hottest data, exactly,
Kelly 0:41
and that's why it's super useful for things like gaming leaderboards or those social media feeds or
Chris 0:48
E commerce recommendations, anything where speed really matters Absolutely.
Kelly 0:51
And it's not just about speed, either. It's about taking some of the pressure off your database by offloading all those requests to read data so
Chris 1:01
your database can focus on more important tasks exactly, and
Kelly 1:04
that also translates to cost savings, so really better performance overall for your application.
Chris 1:09
So it's win win for efficiency and user experience totally. Now to really
Kelly 1:13
understand it, we need to dive into the core features of Elasticache. Okay, let's unpack what makes it work then, all right. Well, the first thing to know is that it supports two main caching engines, memcached and Redis. Okay, you might already be familiar with memcached. It's known for being simple and fast, so
Chris 1:31
Memcached is like a bare bones Speedster. Yeah, exactly
Kelly 1:35
perfect for when you just need quick key value pair access, like
Chris 1:39
session data or user profile, exactly
Kelly 1:41
that sort of thing. Now Redis is a bit more sophisticated. It has a wider array of data structures, including lists sets and sorted sets, okay, so it's more ideal for those complex use cases like real time analytics or leader
Chris 1:58
boards. So Redis brings more tools to the table when you need them, right?
Kelly 2:01
Plus, Redis has persistence options. Oh, okay, so you can store your cache data on disk, which means
Chris 2:08
you don't have to repopulate it if something happens. Nice. So how about different deployment options? I've heard about single node, cLustered and even serverless Elasticache,
Kelly 2:17
yeah. So Elasticache is pretty flexible. It has a few deployment options to fit your needs. Okay, single node is the simplest setup, great for getting started, but if you need more availability, a cLustered deployment is the way to go. So
Chris 2:31
cLustered means you have replicas across multiple nodes Exactly. So
Kelly 2:35
if one fails, your app keeps running like
Chris 2:38
a backup band ready to jump in. Uh huh, yeah, like that. And
Kelly 2:41
then there's serverless Elasticache, okay? And this takes care of all the infrastructure management for you, so you don't have to worry about the servers, right? It scale your capacity up or down based on what's needed. So the
Chris 2:52
serverless option is best if you have unpredictable workloads, yeah, or
Kelly 2:56
for teams that just want to focus on building the application makes sense. And what's really great is that it all integrates perfectly with the rest of the AWS ecosystem. Okay, you can use it with other AWS services like EC2, Lambda S3 it really is a Swiss army knife for performance. That's
Chris 3:14
pretty impressive. It seems like Elasticache has a lot to offer in terms of features and flexibility. Yeah, it does. But Are there limitations to using it? Of course,
Kelly 3:24
it isn't a magic bullet, right? It works best with read heavy workloads, where the data can tolerate being a little stale. So
Chris 3:33
if your app needs that absolute data consistency, it might not
Kelly 3:38
be the best choice, right? You'd probably want to stick with your main
Chris 3:41
database, things like financial transactions where you need that accuracy, exactly. It's
Kelly 3:45
also important to keep in mind costs, especially when dealing with large data sets,
Chris 3:49
because even though it can save you money, picking an oversized instance can counteract that. Yeah, exactly. So it's important to right size your deployment, I guess right now, let's talk a little about how Elasticache might show up on those AWS exams. Sure, we want to help people ace those certifications. Of
Kelly 4:06
course, let's dive into some exam prep. Then, Okay, sounds good. So first off, you really need to know when Elasticache is the right tool. You might see a scenario where an application has performance issues due to lots of reads on the database exactly, and it might ask you to find the best solution, and that's where Elasticache would be the right answer.
Chris 4:27
Recognizing those read heavy workloads is key. What other types of questions might come up?
Kelly 4:32
Well, you'll need to know the differences between memcached and Redis. Okay, it might ask you to pick which one to use based on a specific use case. So
Chris 4:41
if it's something like storing user session data, yeah, then memcached would be the choice because it's simple and fast,
Kelly 4:47
right? But if it involves analytics or leaderboards, you'd pick Redis, because it's got those advanced features exactly. You also need to understand those different deployment options, single node cLuster. And serverless. So
Chris 5:01
based on what the scenario is, you need to pick the right option, right. Okay. What about security? I imagine that would be on the exam.
Kelly 5:07
Definitely. You need to be familiar with VPC endpoints and security groups. Okay, they might ask you to explain how to secure an Elasticache deployment within a VPC so understanding
Chris 5:18
how to keep your data secure and prevent unauthorized access.
Kelly 5:23
Yeah, those are just a few examples. Of course, the exam might go into other areas too, like
Chris 5:29
monitoring, troubleshooting, great. Okay, well, this is really helpful. We've explored what Elasticache is, talked about the strengths and weaknesses, and even touched on how it shows up in those AWS exams. Yeah, I bet our listeners are feeling more confident about Elasticache now. I
Kelly 5:45
hope so, and we're not done yet. Right. In the next part, we're gonna go deeper into those exam style questions, looking at some more complex situations and real world challenges.
Chris 5:55
Great. I'm looking forward to it. See you. Then Welcome back. Are you ready for some more of these Elasticache questions? I
Kelly 6:02
am let's go all right, okay, so let's say you're building this big E commerce platform. You know, millions of users are browsing products, adding stuff to their cart, exactly, especially during those peak shopping seasons. You need to make sure everything is running smoothly,
Chris 6:17
right, even under that heavy load. Yeah.
Kelly 6:19
So how do you think Elasticache could help? Well, we're
Chris 6:22
talking about performance being super important here. We need to handle all those users, yeah, and make sure things like product details and inventory are accessed quickly, right?
Kelly 6:31
And all those database calls to get that data could slow things down, definitely. So
Chris 6:36
I'm thinking Elasticache could cache all that frequently used data. Okay, good. That'll reduce the load on the database and speed things up for the
Kelly 6:45
user. Good start. Now, let's get more specific. What kind of data would you cache? Okay, so
Chris 6:50
things like product details and inventory, those are pretty static, so they could be cached for a while, okay, but things like user cart information, that changes a lot,
Kelly 6:59
yeah, you don't want someone adding something to their cart, and then it's gone right,
Chris 7:02
exactly. So for user carts, we need a shorter TTL, okay, and we need to make sure the cache and the database are in sync, yeah. How would you handle those updates to the cart? Well, we'd need to update that cached cart data whenever the user makes a change, so maybe using message queues or by directly updating the cache. It's a good
Kelly 7:21
thinking. Now, let's switch gears a bit. Imagine you're working on a social media app. It has to display trending topics in real time. What would you think about when using Elasticache for that? Hmm, well,
Chris 7:35
trending topics change really quickly. Yeah. So we need to cache them, but also be able to update and invalidate them fast, right? What about all the data and users, millions of users, are checking those trends. So it needs to be very scalable and always available,
Kelly 7:48
right? How would you actually design your Elasticache setup for that?
Chris 7:52
Well, I think we need a cLustered deployment of Redis. Oh, yeah, because Redis can handle those high speed updates, yeah. And its data structures, like sorted sets, would be perfect for keeping those trends in order.
Kelly 8:03
Good. What about distributing all that load? Ah, right.
Chris 8:07
So we need to use consistent hashing to make sure the data is spread evenly across all the nodes. And Redis Sentinel could monitor if a node fails, right
Kelly 8:16
to make sure you have that automatic failover. You're really thinking about all the important aspects here. Thanks.
Chris 8:21
Okay, I'm feeling good about these scenarios. What else should we cover for the exam? Well, security
Kelly 8:26
is a big one. Yeah, let's say you're putting Elasticache in a VPC, okay, how would you make sure only the right applications and services can get to it?
Chris 8:35
Well, I deploy the cLuster in a private subnet within the VPC, okay, so it's isolated, right? And then I'd use security groups okay to control what traffic can get in and out. Only allow access from specific IP addresses or security groups.
Kelly 8:50
Good. Now, what about VPC endpoints? How would you use those? Right?
Chris 8:54
So we need to connect our VPC to the Elasticache service privately. We don't want it exposed to the internet
Kelly 9:01
Exactly. And
Chris 9:02
why is that important? Well, using VPC endpoints means we don't need a NAT gateway or anything like that, right? The traffic stays inside the AWS network Exactly.
Kelly 9:10
So it's more secure.
Chris 9:11
It's like layers of security, yeah. Okay. So what about monitoring Elasticache?
Unknown Speaker 9:17
Good question. How would you do that? Why
Chris 9:19
do you use CloudWatch? Okay, set up alarms for things like CPU, memory, those cache misses, so if something goes wrong, you'll know exactly. And what metrics would you look at? Yeah, which
Kelly 9:30
specific ones Let
Chris 9:31
me see? Well, definitely, things like cur connections, get misses, evictions, okay, and catch hit rate,
Kelly 9:39
good. Those are some key metrics to keep an eye on, yeah, to
Chris 9:43
see if any adjustments are needed, right? Awesome. This is really helpful. You know, we've covered real world scenarios. We talked about security and even how to monitor everything. Yeah, I feel like I'm understanding how Elasticache works and how to manage it. Great.
Kelly 9:58
Remember knowing how to apply. These concepts is just as important as knowing the definitions for sure. What else we
Chris 10:04
have? Well, let's
Kelly 10:05
talk about some more of those optimization techniques, the things that can really make a difference in a real world application. Sounds
Chris 10:11
good. Let's do it all right. Let's talk about optimizing Elasticache. We've talked about what it is, how it works, and what to watch out
Kelly 10:18
for, right?
Chris 10:19
But how do you actually get it running at peak performance? Yeah, so
Kelly 10:23
tuning your Elasticache deployment can make a huge difference in the real world. Okay, there are a few key areas to focus on right, like, what? Well, first of all, you gotta pick the right instance size. Okay, that makes sense. Elasticache has all these instance types, right? With different CPUs, memory, network capacity, so it's not one size fits all, right? It really depends on your workload. So if I've got a high traffic app with loads of data, you'll need a beefier instance compared to just a simple website, exactly. You really got to think about your usage patterns, okay, how big your data is, how much memory you need, right? Because
Chris 11:01
if you underestimate what you need, you'll run into those bottlenecks Exactly.
Kelly 11:05
And if you get too big of an instance, you're wasting money.
Chris 11:08
True, true. So it's all about finding that balance. Yeah. Another
Kelly 11:12
thing to think about is how your application is accessing the data. Oh, okay, the data access patterns. Can
Chris 11:19
you give me an example of how to optimize that. Sure. One technique is
Kelly 11:23
batching your requests, okay? So instead of sending a bunch of separate requests, group them together into a batch, I see, so it's more efficient, exactly? Yeah. You also want to use the most efficient data structures the right tool for the job, right? So, like, if you're always getting data that needs to be sorted, use a red assorted set rather than a list. Yeah. Pipelining is another cool technique. What's that? You send a bunch of commands to the cache all at once, okay? And you don't wait for a response after each one. This is much faster, way faster, especially if you have a lot to do. Makes sense? Now, let's talk about some of those cache specific settings, right? There are a few things you can tweak, like the eviction policy, okay,
Chris 12:04
so when the cache gets full, this decides what gets kicked out. Exactly.
Kelly 12:09
How does it decide? Well, there are a bunch of different policies, each with pros and cons. You pick the one that works for your application. Okay, so how about the TTL right the time to live? Yeah, This controls how long data stays in the cache. It's super important for keeping your data fresh, but if you set it too short, you're going back to the database too often, right? Which slows things down. Yeah. And if the TTL is too long, your data gets stale. So what's the right balance? Well, it depends. It's about finding that sweet spot for your needs. Okay,
Chris 12:39
any other settings I should know? Well,
Kelly 12:41
there's the max number of connections allowed, so that limits how many clients can connect to the cLuster at the same time. So if it's too low, you can't handle as many users. But too high, it could overload the system, right?
Chris 12:55
Okay, so we've got the instant size data access and all these settings to think about, right? Sounds like a lot to keep track of, yeah, and
Kelly 13:02
don't forget that optimization isn't a one time thing, right? It's ongoing. Your app changes, your traffic changes. You gotta adjust your elastic cache too.
Chris 13:11
So monitoring and troubleshooting are important. Definitely remember
Kelly 13:14
CloudWatch, yep, make sure you've got those alarms set up, okay, for what? CPU, memory hit rate, all that, so we'll be notified if anything is off, exactly, and don't forget to check those logs, right? Elasticache gives you detailed logs to help you troubleshoot. This
Chris 13:30
is all so helpful, I feel much more prepared to actually use Elasticache now.
Kelly 13:35
Good. That's the goal. Remember, optimizing for performance is all about understanding your app right understanding your workload and understanding Elasticache itself,
Chris 13:45
but with the right planning and monitoring, we can really make use of this. You got it. Thank you so much for taking the time to walk us through Elasticache. You're welcome. I've learned so much
Unknown Speaker 13:54
to all our listeners. Keep
Chris 13:56
those caches warm and your app's running smoothly until next time. Happy caching. You.