# Apache Kafka vs Solace

**Leader by Vioscale score:** Apache Kafka

| Attribute | Apache Kafka | Solace |
|---|---|---|
| **Vioscale score** | 57.6 (51% (medium)) | 47.8 (7% (low)) |
| activity.commits_last_30d | 100 | - |
| adoption.dependent_repos | 1 | - |
| adoption.github_stars | 33,629 | - |
| adoption.package_downloads_weekly | 5,508,093 | - |
| deployment.options | `{"self_hosted":true}` | `{"cloud":true,"self_hosted":true}` |
| description.long | Apache Kafka is a free system for capturing, storing, and processing data streams in real time. It enables organizations to reliably move large volumes of data between applications and systems, with support for transformations, aggregations, and stateful processing. | A messaging service that enables developers to create event-driven applications and microservices using multiple programming languages and open protocols (MQTT, REST, JMS, proprietary Direct) across cloud and self-hosted deployment options. |
| features.capabilities | `{"hosting":"self","ordering":"per_partition","paradigm":"pubsub","protocol":"Binary over TCP (SSL/SASL for authentication/encryption)","message_replay":true,"persistent_log":true,"consumer_groups":true,"geo_replication":true,"kafka_compatible":true,"managed_offering":false,"stream_processing":true,"delivery_guarantee":"exactly_once","horizontal_scaling":true}` | `{"hosting":"both","ordering":"per_partition","paradigm":"pubsub","protocol":"MQTT, REST, JMS, Direct","persistent_log":false,"consumer_groups":true,"managed_offering":true,"delivery_guarantee":"at_most_once","horizontal_scaling":true}` |
| integrations.count | 4 | 4 |
| integrations.list | `[{"name":"Postgres"},{"name":"JMS"},{"name":"Elasticsearch"},{"name":"AWS S3"}]` | `[{"name":"AWS"},{"name":"Kafka"},{"name":"Spark"},{"name":"IBM WebSphere"}]` |
| language.primary | Java | - |
| license.spdx | Apache-2.0 | - |
| market.availability | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"cli":true,"linux":true}` | `{"cli":true,"linux":true}` |
| pricing | `{"type":"open_source","freeTier":true,"sourceUrl":"https://kafka.apache.org","retrievedAt":"2026-08-14T11:04:16.831Z"}` | - |
| pricing.free_tier | yes | - |
| pricing.model | open_source | - |
| pricing.price_level | free | - |
| security.scorecard | 6.1 | - |
| security.vulnerabilities | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=go&package_name=github.com%2Fapache%2Fkafka&per_page=100","last_12m":0,"max_severity":null}` | - |

## Capabilities (Message Queues)

| Capability | Apache Kafka | Solace |
|---|:--:|:--:|
| **Core** |  |  |
| Messaging paradigm | Pub/sub | Pub/sub |
| **Correctness** |  |  |
| Delivery guarantee | Exactly-once | At-most-once |
| Ordering guarantee | Per-partition | Per-partition |
| **Durability** |  |  |
| Durable replayable log | ✓ | ✗ |
| Message replay / rewind | ✓ | - |
| **Interop** |  |  |
| Wire protocol | Binary over TCP (SSL/SASL for authentication/encryption) | MQTT, REST, JMS, Direct |
| Kafka-protocol compatible | ✓ | - |
| **Scale** |  |  |
| Partitioned horizontal scaling | ✓ | ✓ |
| Geo / cross-region replication | ✓ | - |
| **Consumption** |  |  |
| Consumer groups / competing consumers | ✓ | ✓ |
| Dead-letter queue | - | - |
| **Deployment** |  |  |
| Managed cloud offering exists | ✗ | ✓ |
| Hosting | Self-hosted only | Cloud + self-hosted |
| **Processing** |  |  |
| Built-in stream processing | ✓ | - |

*Source: Vioscale. Generated 2026-09-01T20:46:07.477Z. "-" = undocumented, not absent.*