-
-
Notifications
You must be signed in to change notification settings - Fork 55
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
This change includes a ton of improvements to the docs in preparation of 1.3 * Add a limitations page (Fixes #39) * Update CloudFormation deployment to use Launch Templates (Fixes #57) * Add a page detailing bandwidth limits for various instance types (Fixes #60) * Add documentation for new 1.3 features (Fixes #64)
- Loading branch information
1 parent
c887089
commit f1130da
Showing
11 changed files
with
4,483 additions
and
45 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1 @@ | ||
| ko_fi: codebrewed |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,102 @@ | ||
| # Choosing an Instance Size | ||
|
|
||
| It can be a bit difficult to understand what instance size is best for your needs when considering a fck-nat instance, | ||
| but if you keep in mind a few key rules, the decision should be relatively straightforward. We also include some | ||
| baseline recommendations below. | ||
|
|
||
| The rules of EC2 to internet networking: | ||
|
|
||
| 1. Most instances offer bandwidth "Up to" a certain amount. This is their burst capacity. Their baseline is | ||
| **signigicantly** smaller. The baseline value is available via the EC2 `describe-instance-types` API. | ||
| 2. Instances with fewer than 32 vCPUs are limited to a maximum of 5Gbps egress to the internet. | ||
| 3. Instances with >=32 vCPUs are allowed 50% their baseline bandwidth out to the internet. | ||
|
|
||
| Alright, now that we have those rules down, what's the best option for you? It's suggested that you read all of the | ||
| sections below before jumping to the one you need because there's a lot of good information spread throughout that | ||
| could help in your decision making, but here's a summary table: | ||
|
|
||
| | Bandwidth | Instance type | Price per Month | | ||
| | --------- | ------------- | --------------- | | ||
| | 3.2Mbps | t4g.nano | $3.06 | | ||
| | 6.4Mbps | t3.micro | $7.59 | | ||
| | 1.6Gbps | c6gn.medium | $32.81 | | ||
| | 3.125Gbps | c7gn.medium | $48.25 | | ||
| | 5Gbps | c7gn.large | $132.20 | | ||
| | 25Gbps | r6in.8xlarge | $1074.56 | | ||
| | 50Gbps | c7gn.8xlarge | $1457.66 | | ||
|
|
||
| Yes, there's some big jumps there. No, there's not really any sensible option in between. | ||
|
|
||
| ### I want to spend less than $10 per month on a NAT solution | ||
|
|
||
| For you my friend, we have the `t4g.nano`. Not only is the `t4g.nano` the least expensive option out of all instance | ||
| types, it also has the highest Gbps/dollar ratio of all the options under $10! The `t4g.nano` supports a burst | ||
| bandwidth of up to 5Gbps and a sustained bandwidth of 3.2Mbps for $3.06/month. | ||
|
|
||
| If you're looking for an option that's a little more expensive but has a higher sustained bandwidth, the `t3.micro` is | ||
| $7.59/month and supports a sustained bandwidth of 6.4Mbps. | ||
|
|
||
| ### I need at least 1Gbps sustained egress | ||
|
|
||
| You have two really good options here. The `c6gn.medium` offers a sustained bandwidth of 1.6 Gbps for $32.81/month | ||
| which is the lowest price available for any instance supporting >1Gbps egress. | ||
|
|
||
| If you're willing to spend a little more, you can get the Rolls Royce of NAT instances, the `c7gn.medium`. The | ||
| `c7gn.medium` supports a whopping 3.125Gbps sustained bandwidth and boasts **the highest Gbps/dollar ration out of | ||
| any instance type in AWS** for $48.25/month | ||
|
|
||
| ### How about 5Gbps sustained egress? | ||
|
|
||
| If you want to hit the max (at <32vCPUs) sustained capacity of 5Gbps out to the internet then your best option is the | ||
| `c7gn.large` which offers 5Gbps sustained for $132.20/month. | ||
|
|
||
| ### I need **more** | ||
|
|
||
| Remember, once you're looking to top 5Gbps, you have to look at instance types with at least 32 vCPUs. This means that | ||
| you're looking at a significant price jump. At this point, it is worthwhile considering sticking to NAT Gateway, but | ||
| there's definitely high total throughput cases which warrant rolling your own NAT at this scale. | ||
|
|
||
| The lowest priced instance offering more than 5Gbps egress is the `c6g.8xlarge` for $794.42/month and offering...6Gbps. | ||
| Once you start getting to this level though, the scaling function actually becomes really straightforward because AWS | ||
| offers dedicated networking at known increments: 12Gbps (like the `c6g.8xlarge` up there), 25Gbps, 50Gbps, and 100Gbps. | ||
| Remember, at >=32vCPUs you're only getting 50% egress bandwidth so the effective values are really 6Gbps, 12.5Gbps, | ||
| 25Gbps, and 50Gbps | ||
|
|
||
| Here's the instance types offering the best value at each of those additional levels: | ||
|
|
||
| | Bandwidth | Instance type | Price per Month | | ||
| | --------- | ------------- | --------------- | | ||
| | 6Gbps | c6g.8xlarge | $794.42 | | ||
| | 12.5Gbps | m5n.8xlarge | $1510.37 | | ||
| | 25Gbps | r6in.8xlarge | $1074.56 | | ||
| | 50Gbps | c7gn.8xlarge | $1457.66 | | ||
|
|
||
| As you can see, 6Gbps and 12.5Gbps are simply not economical options when compared to the best 5Gbps and 25Gbps | ||
| options. So you're effectively looking at jumping straight from 5Gbps to 25Gbps if you need higher sustained | ||
| bandwidth. | ||
|
|
||
| ??? note "How were these values calculated?" | ||
| Through some pain, effort, and a lot of `jq` you can produce the source data on your own and perform your own | ||
| analysis on instance types. The scripts below will pull network bandwidth information from the EC2 API and pricing | ||
| information from the pricing API then combine them along with a `max_egress` value that takes into account the | ||
| rules above and a `ratio` value which is effectively Gbps per dollar and is used as a measurement of "value" | ||
|
|
||
| ```shell | ||
| aws ec2 describe-instance-types \ | ||
| --output json \ | ||
| | jq '.InstanceTypes[] | { (.InstanceType): { vcpus: .VCpuInfo.DefaultVCpus, baseline: .NetworkInfo.NetworkCards[0].BaselineBandwidthInGbps, burst: .NetworkInfo.NetworkPerformance}}' \ | ||
| | jq -s add > instance-networking.json | ||
|
|
||
|
|
||
| aws pricing get-products \ | ||
| --service-code AmazonEC2 \ | ||
| --filters "Type=TERM_MATCH,Field=location,Value=US East (N. Virginia)" \ | ||
| --region us-east-1 \ | ||
| | jq -rc '.PriceList[]' \ | ||
| | jq -r '{ (.product.attributes.instanceType): { price: (.terms.OnDemand[].priceDimensions[].pricePerUnit.USD | tonumber) }}' \ | ||
| | jq -s add > instance-pricing.json | ||
|
|
||
| jq -s '.[0] * .[1]' instance-pricing.json instance-networking.json \ | ||
| | jq 'with_entries(select(.value | has("baseline") and has("price") and .price > 0.0))' \ | ||
| | jq 'to_entries | map(.value |= . + {max_egress: (if .vcpus < 32 then ([.baseline, 5.0] | min) else .baseline / 2 end) }) | map(.value |= . + {ratio: (.max_egress / (.price | tonumber)), price_monthly: (.price * 730)}) | sort_by(.value.ratio) | from_entries' > instance-merged.json | ||
| ``` |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,16 +1,29 @@ | ||
| # fck-nat Configuration | ||
|
|
||
| ## Configuration file | ||
| ## Configuration File | ||
|
|
||
| Upon starting, fck-nat evaluates a configuration file describing how the instance should behave as well as what features | ||
| shall be enabled. To configure fck-nat, ensure a file `/etc/fck-nat.conf` exists with your configuration. fck-nat | ||
| requires the service to be restarted by running `service fck-nat-resart`. In most implementations this configuration is | ||
| requires the service to be restarted by running `systemctl restart fck-nat.service`. In most implementations this configuration is | ||
| passed only once via EC2's user data. | ||
|
|
||
| The following describes available options: | ||
| | name | description | | ||
|
|
||
| | Name | Description | | ||
| | ----------------------- | ----------- | | ||
| | `eni_id` | The ID of the Elastic Network Interface to attach to the instance and use as a consistent endpoint to send traffic to fck nat. This is required when using high-availability mode. | | ||
| | `eip_id` | The ID of an Elastic IP to be attached to the public network interface. This ensures the NAT gateway public traffic is always routed through the same public IP address. | | ||
| | `cwagent_enabled` | If set, enables Cloudwatch agent and forward instance metrics to Cloudwatch. Requires `cwagent_cfg_param_name` to be set. | | ||
| | `cwagent_cfg_param_name` | The name of the SSM Parameter holding the Cloudwatch agent configuration and which the agent shall pull from. Requires `cwagent_enabled` to be set. | | ||
|
|
||
| ## IAM Requirements | ||
|
|
||
| Certain features of fck-nat require the role attached to the instance to have permissions for certain AWS API | ||
| operations. The table below details the current permission requirements for various features: | ||
|
|
||
| | Feature | Required Permissions | | ||
| | ------- | -------------------- | | ||
| | HA-mode (`eni_id`) | `ec2:AttachNetworkInterface, ec2:ModifyNetworkInterfaceAttribute` | | ||
| | Static IP (`eip_id`) | `ec2:AssociateAddress, ec2:DisassociateAddress` | | ||
| | Cloudwatch Agent (`cwagent_enabled`) | Managed Policy: `CloudWatchAgentServerPolicy` *and* `ssm:GetParameter` | | ||
| | SSM Agent (installed by default, IAM role required to use) | Managed Policy: `AmazonSSMManagedEC2InstanceDefaultPolicy` | |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.