Persistence
Overview
When running Weaviate with Docker or Kubernetes, you can persist its data by mounting a volume to store the data outside of the containers. Doing so will cause the Weaviate instance to also load the data from the mounted volume when it is restarted.
Note that Weaviate now offers native backup modules starting with v1.15
for single-node instances, and v1.16
for multi-node instances. For older versions of Weaviate, persisting data as described here will allow you to back up Weaviate.
Docker Compose
Persistence
When running Weaviate with Docker Compose, you can set the volumes
variable under the weaviate
service and a unique cluster hostname as an environment variable.
services:
weaviate:
volumes:
- /var/weaviate:/var/lib/weaviate
environment:
CLUSTER_HOSTNAME: 'node1'
- About the volumes
/var/weaviate
is the location where you want to store the data on the local machine/var/lib/weaviate
(after the colon) is the location inside the container, don't change this
- About the hostname
- The
CLUSTER_HOSTNAME
can be any arbitrarily chosen name
- The
In the case you want a more verbose output, you can change the environment variable for the LOG_LEVEL
services:
weaviate:
environment:
LOG_LEVEL: 'debug'
A complete example of a Weaviate without modules but with an externally mounted volume and more verbose output:
---
version: '3.4'
services:
weaviate:
command:
- --host
- 0.0.0.0
- --port
- '8080'
- --scheme
- http
image: semitechnologies/weaviate:1.22.5
ports:
- 8080:8080
restart: on-failure:0
volumes:
- /var/weaviate:/var/lib/weaviate # <== set a volume here
environment:
QUERY_DEFAULTS_LIMIT: 25
AUTHENTICATION_ANONYMOUS_ACCESS_ENABLED: 'true'
PERSISTENCE_DATA_PATH: '/var/lib/weaviate'
DEFAULT_VECTORIZER_MODULE: 'none'
ENABLE_MODULES: ''
CLUSTER_HOSTNAME: 'node1' # <== this can be set to an arbitrary name
...
Backups
See Backups.
Kubernetes
For Kubernetes setup, the only thing to bear in mind is that Weaviate needs a PersistentVolumes
through PersistentVolumeClaims
(more info) but the Helm chart is already configured to store the data on an external volume.
Disk Pressure Warnings and Limits
Starting with v1.12.0
there are two levels of disk usage notifications and actions configured through environment variables. Both variables are optional. If not set they default to the values outlined below:
Variable | Default Value | Description |
---|---|---|
DISK_USE_WARNING_PERCENTAGE | 80 | If disk usage is higher than the given percentage a warning will be logged by all shards on the affected node's disk |
DISK_USE_READONLY_PERCENTAGE | 90 | If disk usage is higher than the given percentage all shards on the affected node will be marked as READONLY , meaning all future write requests will fail. |
If a shard was marked READONLY
due to disk pressure and you want to mark the
shard as ready again (either because you have made more space available or
changed the thresholds) you can use the Shards API to do so.
Virtual memory access method
v1.21
You can choose between mmap
(DEFAULT) and pread
functions to access virtual memory by setting the PERSISTENCE_LSM_ACCESS_STRATEGY
environment variable.
The two functions reflect different under-the-hood memory management behaviors. mmap
uses a memory-mapped file, which means that the file is mapped into the virtual memory of the process. pread
is a function that reads data from a file descriptor at a given offset.
In general, mmap
may be a preferred option with memory management benefits. However, if you experience stalling situations under heavy memory load, we suggest trying pread
instead.