# Sentry Node Architecture Overview

**URL:** <https://forum.cosmos.network/t/sentry-node-architecture-overview/454>\
**Category:** Validation\
**Created:** [July 11, 2018, 10:04pm UTC](https://forum.cosmos.network/t/sentry-node-architecture-overview/454 "2018-07-11T22:04:58Z")\
**Posts on this page:** 1\
**Showing post:** 17

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**Author:** ![kwunyeung](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.cosmos.network/kwunyeung/32/68_2.png) [@kwunyeung](https://forum.cosmos.network/u/kwunyeung)\
**Post date:** [July 14, 2018, 6:16am UTC](https://forum.cosmos.network/t/sentry-node-architecture-overview/454/17 "2018-07-14T06:16:46Z")

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> [@Greg](#):
>
> One thing I don’t like is that a sentry node only becomes useful when the validator node is updated (Sentry node added to **persistent\_peers** on the validator.)

What @Greg wanna explain was that when there is a new sentry, the node address has to be updated on `persistent_peers` of the validator node. Otherwise, the new sentry node won’t be useful as the validator node is not talking to the new sentry node.

> [@Greg](#):
>
> Currently, this is only possible during a maintenance schedule of the validator, since it requires the validator to be restarted.

He meant the validator node has to be restarted as the config.toml file was updated with the new sentry node address.

@Greg there is a way to avoid restarting the validator node which is to add the a new peer using the `/dial_peers` endpoint. @jack has mentioned about this in the following thread.

> [@Sentry nodes - What they are! - How they work! - Why they exist!](https://forum.cosmos.network/t/sentry-nodes-what-they-are-how-they-work-why-they-exist/379/14):
>
> @katernoir [This doc](https://github.com/tendermint/tendermint/blob/master/docs/using-tendermint.md) has some more information about the /dial\_peers endpoint. You need to enable it by setting [rpc]unsafe = true in your config.toml. Also for enabling autoscaling you will need to be taking regular snapshots of full node state in order to quickly spin up nodes. I’ve got a high-level overview on how to do this using GCE in a [notes github repo](https://github.com/jackzampolin/cosmos-autoscale#autoscaling-sentry-node-architecture-on-gce). @mattharrop Looks like this issue will be fixed by the external\_addr option added to the config. That will be available for the upcomi…

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