warp append

Test S3 Express append operations to measure incremental object growth performance.

Synopsis

Syntax

warp append [FLAGS]

The append command benchmarks S3 Express One Zone append operations. This command tests the performance of appending data incrementally to existing objects. S3 Express append operations require checksums that support CRC merging.

Example

warp append --host s3express.example.com:443 --tls --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

Run a basic append benchmark against an S3 Express endpoint. The command creates objects and repeatedly appends data to measure incremental write performance.

Flags

Command-specific flags

`--obj.size`

Default: 10MiB

Size of each append operation added to the object. The command appends data of this size repeatedly during the benchmark duration. Use this flag to test append performance with different data sizes.

Valid formats include numbers or values with KiB, MiB, or GiB suffixes (base 2 binary).

Example:

warp append --host s3express.example.com:443 --tls --obj.size 1MiB --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

Shared flags

This command supports all common flags including connection, performance, object, upload, benchmark control, analysis, and monitoring flags.

Benchmark behavior

The append benchmark creates objects in the target bucket and performs repeated append operations. Each append adds data of the specified size to the end of existing objects. The benchmark measures throughput, latency, and operation success rates for append operations.

S3 Express One Zone Required

This benchmark requires S3 Express One Zone storage class. Append operations do not work with standard S3 storage or versioned buckets.

S3 Express append operations automatically use CRC64NVME checksums unless you specify a different checksum algorithm. The checksum algorithm must support CRC merging for append operations to function correctly. The command sets the full object checksum flag to validate data integrity across all appends.

Output

The append benchmark provides performance metrics for incremental object writes.

The output includes operations per second showing how many append operations complete. Throughput metrics display the data transfer rate in MB/s for all append operations. Latency percentiles show response times at p50, p90, p99, and p99.9 levels.

The benchmark reports error rates for failed append operations. Object growth metrics show how quickly objects increase in size during the test. S3 Express specific metrics reveal performance characteristics unique to the storage class.

Examples

Basic append test

Test append operations with default settings:

warp append --host s3express.example.com:443 --tls --access-key ACCESS_KEY --secret-key SECRET_KEY

The command runs for the default duration and appends 10MiB chunks repeatedly.

Small append operations

Test append performance with smaller data sizes:

warp append --host s3express.example.com:443 --tls --obj.size 256KiB --duration 5m --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

This tests incremental append performance similar to log file or event stream writes.

Large append operations

Test append performance with larger data chunks:

warp append --host s3express.example.com:443 --tls --obj.size 50MiB --concurrent 10 --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

This tests performance for applications that append substantial data blocks.

High concurrency test

Test append operations with multiple concurrent threads:

warp append --host s3express.example.com:443 --tls --concurrent 50 --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

This reveals how the system handles many simultaneous append operations.

Custom checksum algorithm

Test append operations with a specific checksum:

warp append --host s3express.example.com:443 --tls --checksum CRC32C --access-key YOUR_ACCESS_KEY --secret-key YOUR_SECRET_KEY

The checksum must support CRC merging for append operations.