Databases

Supercharge your Cloud SQL for MySQL write performance with new optimized writes

January 5, 2026

Alex Joseph

Senior Software Engineering Manager

Somdyuti Paul

Data Management Specialist

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Tuning MySQL instances for write-intensive workloads is a persistent engineering challenge. Cloud SQL for MySQL Enterprise Plus edition now includes optimized writes, a set of automated features that adjust MySQL configurations based on real-time workload and infrastructure metrics. This reduces write latency and increases throughput without manual intervention.

All Enterprise Plus edition instances have this feature enabled by default. This post details the underlying optimizations and provides a reproducible benchmark to measure the performance improvements.

Inside Cloud SQL for MySQL optimized writes

The optimized writes feature includes five different optimizations that all automatically tune MySQL parameters, flags, and data handling, in order to optimize write performance based on instance and workload needs. Here’s a little more about how each component of optimized writes works:

Feature	What it does
Adaptive purge	Cloud SQL dynamically adjusts innodb_purge_threads to prioritize user workloads over routine database maintenance operations.
Adaptive I/O limits	Cloud SQL dynamically adjusts I/O parameters, specifically innodb_io_capacity and innodb_io_capacity_max. This adjustment occurs in direct response to fluctuations in workload demands and prevents I/O bottlenecks during traffic spikes.
Scalable sharded I/O	Cloud SQL implements I/O sharding by distributing load across multiple mutexes to enhance I/O throughput and accommodate demanding workloads.
Faster REDO recovery	Cloud SQL optimizes the handling of temporary data and the expedited flushing of dirty pages, consequently reducing recovery times and enabling the utilization of larger redo logs.
Adaptive buffer pool warmup	Cloud SQL dynamically uses available disk I/O capacity to accelerate data cache warmup by scheduling page reads, resulting in faster data cache warmup post instance restart and a reduction in performance variance.

We've observed that with optimized writes, Cloud SQL for MySQL Enterprise Plus now delivers up to 3x better write throughput when compared to its Enterprise edition counterpart, while reducing latency significantly. These optimizations are most effective for write-intensive OLTP workloads and results can vary based on machine configurations. For workloads that are primarily read, Cloud SQL Enterprise Plus edition also provides an integrated SSD-backed data cache option, enabling up to 3x higher read throughput, as detailed in our initial launch blog.

https://storage.googleapis.com/gweb-cloudblog-publish/images/image1_Evrsw9B.max-600x600.png

Testing the optimized write performance improvement

Now that you're aware of the exceptional write performance offered by Cloud SQL for MySQL Enterprise Plus edition, you might be curious about its potential impact within your own environment. Measuring this performance enhancement can be done with the sysbench benchmarking tool. You can follow the steps below and adjust specific machine configuration parameters to conduct testing tailored to your typical workloads.

Step 1: Create database instances
To help study the performance improvement, first create three different class of machines:

Enterprise edition (ee)
Enterprise Plus edition (ee+) without optimized writes
Enterprise Plus edition (ee+) with optimized writes

# will set some basic configuration variables to help us run things with higher scalability.

#------------------------------------------------------
# ee
gcloud sql instances create ee --database-version="MYSQL_8_0_37" --availability-type=zonal --edition=ENTERPRISE --cpu=64 --memory=416GB --storage-size=3000 --storage-type=SSD --zone="us-central1-c" --network=projects/${PROJECT}/global/networks/default --no-assign-ip --enable-google-private-path --no-enable-bin-log --database-flags="max_prepared_stmt_count=1000000,innodb_adaptive_hash_index=off,innodb_flush_neighbors=0,table_open_cache=200000"

#------------------------------------------------------
# ee+ without optimized writes
# Note: this configuration is not recommended and being shown only for comparison
# without optimized write larger redo log size will cause longer recovery time so switch back the redo log size to what it was originally (before optimized write was introduced).
gcloud sql instances create eeplusow0 --database-version="MYSQL_8_0_37" --availability-type=zonal --edition=ENTERPRISE_PLUS --tier=db-perf-optimized-N-64 --storage-size=3000 --storage-type=SSD --zone="us-central1-c" --network=projects/${PROJECT}/global/networks/default --no-assign-ip --enable-google-private-path --no-enable-bin-log  --database-flags="max_prepared_stmt_count=1000000,innodb_adaptive_hash_index=off,innodb_flush_neighbors=0,table_open_cache=200000,innodb_cloudsql_optimized_write=off,innodb_log_file_size=1073741824"

#------------------------------------------------------
# ee+ with optimized writes
gcloud sql instances create eeplusow1 --database-version="MYSQL_8_0_37" --availability-type=zonal --edition=ENTERPRISE_PLUS --tier=db-perf-optimized-N-64 --storage-size=3000 --storage-type=SSD --zone="us-central1-c" --network=projects/${PROJECT}/global/networks/default --no-assign-ip --enable-google-private-path --no-enable-bin-log  --database-flags="max_prepared_stmt_count=1000000,innodb_adaptive_hash_index=off,innodb_flush_neighbors=0,table_open_cache=200000"

Step 2: Create client
Next, create a VM for the client instance. Client instances are placed in the same region but different zone.

# Note: Best practice is to benchmark instances at the same time. To do so, create three separate client instances.

Then, log in to the client instances and execute following commands to install sysbench and mysqladmin:

# Note: We use the latest sysbench binaries with all the fixes.

Step 3: Run the benchmarking workload
Finally, you can run the sysbench write benchmark using the following script:

#!/bin/bash

# write-workload.sh

HOST=HOST_IP_ADDRESS
sysbenchdir="$HOME/sysbench/installed/"
mysqlclidir="/usr/bin"
mysqluser="root"
mysqlpasswd="pas$w0rd"

rows=("12000000")

for (( k=1; k<=4; k+=1 ))
do
  for row in ${rows[@]};
  do
     #------------
     # step-1: load data
     $mysqlclidir/mysql -u $mysqluser -h $HOST -e "drop database if exists x86; create database if not exists x86;"
     $sysbenchdir/bin/sysbench --threads=100 --mysql-host=$HOST --mysql-port=3306 --mysql-db=x86 --mysql-user=$mysqluser --mysql-password=$mysqlpasswd $sysbenchdir/share/sysbench/oltp_insert.lua --tables=100 --table-size=$row prepare
     $sysbenchdir/bin/sysbench --threads=128 --events=10000000 --time=0 --report-interval=10 --mysql-host=$HOST --mysql-port=3306 --mysql-db=x86 --mysql-user=$mysqluser --mysql-password=$mysqlpasswd $sysbenchdir/share/sysbench/oltp_update_index.lua --tables=100 --table-size=$row run
     sleep 300

#------------
     # step-2: start write benchmarking workload
    for (( i=128; i<=512; i*=2 ))
     do
       $sysbenchdir/bin/sysbench --threads=$i --time=3600 --report-interval=10 --mysql-host=$HOST --mysql-port=3306 --mysql-db=x86 --mysql-user=$mysqluser --mysql-password=$mysqlpasswd $sysbenchdir/share/sysbench/oltp_write_only.lua --tables=100 --table-size=$row run
       sleep 120
    done
     $mysqlclidir/mysql -u root -h $HOST -e "drop database if exists x86;"
  done
done

Upon completion, you will observe the throughput and latency results from the three Cloud SQL instances created in Step 1. These results should demonstrate the performance advantages of the Enterprise Plus edition and further improvements brought by optimized writes. Please note that performance outcomes can fluctuate and may vary based on specific machine configurations.

Ready to enable optimized writes?

All existing and newly created instances have optimized writes enabled by default, so upgrade your Cloud SQL instances to Enterprise Plus edition today to experience the performance improvement!

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