taigrr/nats.docs
1
0
Fork 0
mirror of https://github.com/taigrr/nats.docs synced 2025-01-18 04:03:23 -08:00
Code Issues Projects Releases Wiki Activity

updates based on RI changes to README

Browse Source
This commit is contained in:
Ginger Collison 2021-02-11 15:56:18 -06:00 committed by GitHub
parent a3224f0245
commit 2b9d45ad7e
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 90 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

92
jetstream/clustering/administration.md
View File

@ -2,6 +2,10 @@
Once a JetStream cluster is operating interactions with the CLI and with `nats` CLI is the same as before. For these examples, lets assume we have a 5 server cluster, n1-n5 in a cluster named C1.
## Account Level
Within an account there are operations and reports that show where users data is placed and which allow them some basic interactions with the RAFT system.
## Creating clustered streams
When adding a stream using the `nats` CLI the number of replicas will be asked, when you choose a number more than 1, (we suggest 1, 3 or 5), the data will be stored o multiple nodes in your cluster using the RAFT protocol as above.
@ -32,7 +36,26 @@ The `current` indicates that followers are up to date and have all the messages,
The replica count cannot be edited once configured.
## Forcing Stream and Consumer leader election
### Viewing Stream Placement and Stats
Users can get overall statistics about their streams and also where these streams are placed:
```
$ nats stream report
Obtaining Stream stats
+----------+-----------+----------+--------+---------+------+---------+----------------------+----------+
| Stream | Consumers | Messages | Bytes | Storage | Lost | Deleted | Cluster | Template |
+----------+-----------+----------+--------+---------+------+---------+----------------------+----------+
| ORDERS | 4 | 0 | 0 B | File | 0 | 0 | n1-c1*, n2-c1, n3-c1 | |
| ORDERS_3 | 4 | 0 | 0 B | File | 0 | 0 | n1-c1*, n2-c1, n3-c1 | |
| ORDERS_4 | 4 | 0 | 0 B | File | 0 | 0 | n1-c1*, n2-c1, n3-c1 | |
| ORDERS_5 | 4 | 0 | 0 B | File | 0 | 0 | n1-c1, n2-c1, n3-c1* | |
| ORDERS_2 | 4 | 1,385 | 13 MiB | File | 0 | 1 | n1-c1, n2-c1, n3-c1* | |
| ORDERS_0 | 4 | 1,561 | 14 MiB | File | 0 | 0 | n1-c1, n2-c1*, n3-c1 | |
+----------+-----------+----------+--------+---------+------+---------+----------------------+----------+
```
#### Forcing Stream and Consumer leader election
Every RAFT group has a leader that's elected by the group when needed. Generally there is no reason to interfere with this process, but you might want to trigger a leader change at a convenient time. Leader elections will represent short interruptions to the stream so if you know you will work on a node later it might be worth moving leadership away from it ahead of time.
@ -55,6 +78,71 @@ Cluster Information:
The same is true for consumers, `nats consumer cluster step-down ORDERS NEW`.
## System Level
Systems users can view state of the Meta Group - but not individual Stream or Consumers.
### Viewing the cluster state
We have a high level report of cluster state:
```nohighlight
$ nats server report jetstream --user system
+--------------------------------------------------------------------------------------------------+
| JetStream Summary |
+--------+---------+---------+-----------+----------+--------+--------+--------+---------+---------+
| Server | Cluster | Streams | Consumers | Messages | Bytes | Memory | File | API Req | API Err |
+--------+---------+---------+-----------+----------+--------+--------+--------+---------+---------+
| n3-c2 | c2 | 0 | 0 | 0 | 0 B | 0 B | 0 B | 1 | 0 |
| n3-c1 | c1 | 6 | 24 | 2,946 | 27 MiB | 0 B | 27 MiB | 3 | 0 |
| n2-c2 | c2 | 0 | 0 | 0 | 0 B | 0 B | 0 B | 3 | 0 |
| n1-c2 | c2 | 0 | 0 | 0 | 0 B | 0 B | 0 B | 14 | 2 |
| n2-c1 | c1 | 6 | 24 | 2,946 | 27 MiB | 0 B | 27 MiB | 15 | 0 |
| n1-c1* | c1 | 6 | 24 | 2,946 | 27 MiB | 0 B | 27 MiB | 31 | 0 |
+--------+---------+---------+-----------+----------+--------+--------+--------+---------+---------+
| | | 18 | 72 | 8,838 | 80 MiB | 0 B | 80 MiB | 67 | 2 |
+--------+---------+---------+-----------+----------+--------+--------+--------+---------+---------+
+---------------------------------------------------+
| RAFT Meta Group Information |
+-------+--------+---------+---------+--------+-----+
| Name | Leader | Current | Offline | Active | Lag |
+-------+--------+---------+---------+--------+-----+
| n1-c1 | yes | true | false | 0.00s | 0 |
| n1-c2 | | true | false | 0.05s | 0 |
| n2-c1 | | true | false | 0.05s | 0 |
| n2-c2 | | true | false | 0.05s | 0 |
| n3-c1 | | true | false | 0.05s | 0 |
| n3-c2 | | true | false | 0.05s | 0 |
+-------+--------+---------+---------+--------+-----+
```
This is a full cluster wide report, the report can be limited to a specific account using `--account`.
Here we see the distribution of streams, messages, api calls etc by across 2 super clusters and an overview of the RAFT meta group.
In the Meta Group report the server `n2-c1` is not current and has not been seen for 9 seconds, it's also behind by 2 raft operations.
This report is built using raw data that can be obtained from the monitor port on the `/jsz` url, or over nats using:
```nohightlight
$ nats server req jetstream --help
...
--name=NAME Limit to servers matching a server name
--host=HOST Limit to servers matching a server host name
--cluster=CLUSTER Limit to servers matching a cluster name
--tags=TAGS ... Limit to servers with these configured tags
--account=ACCOUNT Show statistics scoped to a specific account
--accounts Include details about accounts
--streams Include details about Streams
--consumer Include details about Consumers
--config Include details about configuration
--leader Request a response from the Meta-group leader only
--all Include accounts, streams, consumers and configuration
$ nats server req jetstream --leader
```
This will produce a wealth of raw information about the current state of your cluster - here requesting it from the leader only.
#### Forcing Meta Group leader election
Similar to Streams and Consumers above the Meta Group allows leader stand down. The Meta Group is cluster wide and spans all accounts, therefore to manage the meta group you have to use a `SYSTEM` user.
@ -65,7 +153,7 @@ $ nats server raft step-down --user system
17:44:24 New leader: n1-c2
```
## Evicting a peer
### Evicting a peer
Generally when shutting down NATS, including using Lame Duck Mode, the cluster will notice this and continue to function. A 5 node cluster can withstand 2 nodes being down.