release-26.4: roachtest: perturbation/full/restart failed

roachtest.perturbation/full/restart failed with artifacts on release-26.4 @ b4884d371d74d172ab184bc4ef0924ccb758f3c2:

Failed with:

(assertions.go:388).Fail: 
	Error Trace:	pkg/cmd/roachtest/tests/perturbation/framework.go:1084
	            				pkg/cmd/roachtest/test_runner.go:1992
	            				src/runtime/asm_amd64.s:1771
	Error:      	FAILURE: follower-read  : throughput ratio 6508200000000.00x exceeds limit 1.2x (baseline: 6508 ops/s, measured: 0 ops/s)
	            	FAILURE: read           : throughput ratio 6515200000000.00x exceeds limit 1.2x (baseline: 6515 ops/s, measured: 0 ops/s)
	            	FAILURE: write          : throughput ratio 13090900000000.00x exceeds limit 1.2x (baseline: 13091 ops/s, measured: 0 ops/s)
	            	FAILURE: follower-read  : throughput ratio 1.40x exceeds limit 1.2x (baseline: 6508 ops/s, measured: 4640 ops/s)
	            	FAILURE: read           : throughput ratio 1.39x exceeds limit 1.2x (baseline: 6515 ops/s, measured: 4695 ops/s)
	            	FAILURE: write          : throughput ratio 1.39x exceeds limit 1.2x (baseline: 13091 ops/s, measured: 9397 ops/s)
	Test:       	perturbation/full/restart
(require.go:522).Fail: FailNow called
test artifacts and logs in: /artifacts/perturbation/full/restart/run_1

Cluster Node to Ip Mapping:

Parameters:

• acMode=defaultOption
• arch=amd64
• blockSize=4096
• cloud=gce
• concurrency=500
• coverageBuild=false
• cpu=16
• diskBandwidthLimit=0
• diskCount=2
• disks=2
• encrypted=false
• fillDuration=10m0s
• followerReadPercent=50
• fs=ext4
• leaseType=leader
• localSSD=true
• mem=standard
• numNodes=12
• numWorkloadNodes=1
• perturbationDuration=10m0s
• ratioOfMax=0.3
• readPercent=50
• runtimeAssertionsBuild=false
• seed=0
• splits=10000
• validationDuration=5m0s
• vcpu=16
• workloadConnInit=

Jira issue: CRDB-68546

Start with the failure at pkg/cmd/roachtest/tests/perturbation/framework.go:1084 and the caller in pkg/cmd/roachtest/test_runner.go:1992. Inspect the run_1 artifacts and linked Grafana and Datadog data to determine why throughput falls to zero or below the 1.2x limit during perturbation/full/restart. Done means the failure cause is addressed and this roachtest no longer reports the shown throughput-ratio failures.