microsoft/garnet

DBSIZE takes time in minutes and keyspace info missing when SSD storage tier is enabled

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#1,436 opened on Nov 14, 2025

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help wanted

Description

Describe the bug

When running Garnet v1.0.87 with SSD storage tier enabled, the DBSIZE command becomes extremely slow (5-10 minutes) after loading data. Additionally, the INFO command does not show any keyspace section, even though keys exist in SSD tier.

  • This issue is consistently reproducible.

Steps to reproduce the bug

  1. Start Garnet on a GCP C4D-HighMem-64 machine with the following configuration:
{
  "Port": 6379,
  "Address": "0.0.0.0",
  "MemorySize": "16g",
  "PageSize": "32m",
  "SegmentSize": "4g",
  "IndexSize": "16g",
  "IndexMaxSize": "64g",
  "IndexResizeFrequencySecs": 30,
  "IndexResizeThreshold": 65,
  "EnableReadCache": true,
  "ReadCacheMemorySize": "420g",
  "ReadCachePageSize": "2m",
  "DisableObjects": true,
  "EnableStorageTier": true,
  "LogDir": "/mnt/localssd/garnet/log",
  "CheckpointDir": "/mnt/localssd/garnet/ckpt",
  "Recover": true,
  "EnableAOF": false,
  "CompactionFrequencySecs": 0,
  "LogLevel": "Information",
  "MetricsSamplingFrequency": 10
}
  1. Load ~1.2 GB of data into the SSD tier using:
docker run --rm \
  --cpus="$(nproc)" \
  --memory="$(free -m | awk '/^Mem:/{print int($2*0.95)"m"}')" \
  --network host \
  redislabs/memtier_benchmark:latest \
  -d 256000 \
  --distinct-client-seed \
  -h <garnet_host> \
  --ratio 1:0 \
  --key-maximum 300000000 \
  -c 15 -t "$(nproc)" \
  --test-time 1000
  1. After load is complete:
    • Run DBSIZE → takes 5-10 minutes
    • Run INFO → keyspace section is missing

Expected behavior

  • DBSIZE should return quickly without long blocking durations.
  • INFO should display keyspace details even when keys are stored in SSD tier.

Screenshots

Release version

v1.0.87

IDE

N/A (server-side issue)

OS version

Ubuntu 24.04.3 LTS

Additional context

No response

Contributor guide

Tech stack
csharp
Domain
databaseperformance
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Basic understanding of Garnet's architectureFamiliarity with storage tieringC# programming skills
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate the DBSIZE implementation in Garnet's server code, likely in files such as GarnetServer.cs or related command handling files. Understand why iterating over keys in the SSD tier is slow. For INFO keyspace, check the InfoCommand handler and see if it enumerates only memory keys or also tiered keys. Look at recent commits related to storage tiering. Consider adding a counter for keys in SSD tier. Review the StorageTier class to see if it provides an efficient count. Suggest profiling the DBSIZE operation to identify bottlenecks.