release-26.3: roachtest: perturbation/full/partition failed

roachtest.perturbation/full/partition [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21392022?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21392022?buildTab=artifacts#/perturbation/full/partition) on release-26.3 @ [8a9a8e3305daa0890b7b083c13cb572f911bd6cc](https://github.com/cockroachdb/cockroach/commits/8a9a8e3305daa0890b7b083c13cb572f911bd6cc):

Failed with:

```
(assertions.go:387).Fail:
Error Trace: pkg/cmd/roachtest/tests/perturbation/framework.go:1051
pkg/cmd/roachtest/test_runner.go:1548
src/runtime/asm_amd64.s:1771
Error: FAILURE: follower-read : throughput ratio 1.64x exceeds limit 1.2x (baseline: 10436 ops/s, measured: 6356 ops/s)
FAILURE: read : throughput ratio 1.62x exceeds limit 1.2x (baseline: 10397 ops/s, measured: 6413 ops/s)
FAILURE: write : throughput ratio 1.65x exceeds limit 1.2x (baseline: 20953 ops/s, measured: 12733 ops/s)
Test: perturbation/full/partition
(require.go:522).Fail: FailNow called
test artifacts and logs in: /artifacts/perturbation/full/partition/run_1
```
Cluster Node to Ip Mapping:
| Node | Public IP | Private IP |
| --- | --- | --- |
| teamcity-21392022-1781763104-317-n13cpu16sm-0001 | 34.74.123.170 | 10.142.0.191 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0002 | 35.196.195.136 | 10.142.0.185 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0003 | 34.23.214.156 | 10.142.0.106 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0004 | 34.75.188.172 | 10.142.0.190 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0005 | 35.196.60.41 | 10.142.0.27 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0006 | 34.23.160.170 | 10.142.0.62 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0007 | 34.138.18.43 | 10.142.0.101 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0008 | 34.148.11.128 | 10.142.0.127 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0009 | 34.73.230.145 | 10.142.0.118 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0010 | 35.243.184.20 | 10.142.0.178 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0011 | 35.196.139.56 | 10.142.0.192 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0012 | 35.196.156.238 | 10.142.0.189 |
| teamcity-21392022-1781763104-317-n13cpu16sm-0013 | 34.26.164.63 | 10.142.0.111 |

Parameters:
- acMode=defaultOption
- arch=amd64
- blockSize=4096
- cloud=gce
- coverageBuild=false
- cpu=16
- diskBandwidthLimit=0
- diskCount=2
- disks=2
- encrypted=false
- fillDuration=10m0s
- leaseType=expiration
- mem=standard
- numNodes=12
- numWorkloadNodes=1
- perturbationDuration=10m0s
- ratioOfMax=0.5
- runtimeAssertionsBuild=false
- seed=0
- splits=10000
- validationDuration=5m0s
- vcpu=16
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

See: [Grafana](https://go.crdb.dev/roachtest-grafana/teamcity-21392022/perturbation-full-partition/1781824707287/1781826971246)

See: [Datadog Logs](https://us5.datadoghq.com/logs?query=service%3Aroachtest+%40cluster%3Ateamcity-21392022-1781763104-317-n13cpu16sm&from_ts=1781824707287&to_ts=1781826971246&live=false&storage=flex_tier)

/cc @cockroachdb/kv-triage

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*perturbation/full/partition.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-64933

Start with the linked roachtest README, then inspect pkg/cmd/roachtest/tests/perturbation/framework.go around line 1051 and review the linked build artifacts, Grafana dashboard, and Datadog logs. Determine why the partition test's follower-read, read, and write throughput ratios exceed the 1.2x limit; done means the failure is understood and the test passes reliably.

Written by the indexing model from the issue text.