Configure Message Storage with Milvus Operator
Milvus uses RocksMQ, Pulsar or Kafka for managing logs of recent changes, outputting stream logs, and providing log subscriptions. This topic introduces how to configure message storage dependencies when you install Milvus with Milvus Operator. For more details, refer to Configure Message Storage with Milvus Operator in the Milvus Operator repository.
This topic assumes that you have deployed Milvus Operator.
You need to specify a configuration file for using Milvus Operator to start a Milvus cluster.
kubectl apply -f https://raw.githubusercontent.com/zilliztech/milvus-operator/main/config/samples/milvus_cluster_default.yaml
You only need to edit the code template in milvus_cluster_default.yaml
to configure third-party dependencies. The following sections introduce how to configure object storage, etcd, and Pulsar respectively.
Before you begin
The table below shows whether RocksMQ, NATS, Pulsar, and Kafka are supported in Milvus standalone and cluster mode.
RocksMQ | NATS | Pulsar | Kafka | |
---|---|---|---|---|
Standalone mode | ✔️ | ✔️ | ✔️ | ✔️ |
Cluster mode | ✖️ | ✖️ | ✔️ | ✔️ |
There are also other limitations for specifying the message storage:
- Only one message storage for one Milvus instance is supported. However we still have backward compatibility with multiple message storages set for one instance. The priority is as follows:
- standalone mode: RocksMQ (default) > Pulsar > Kafka
- cluster mode: Pulsar (default) > Kafka
- Nats introduced in 2.3 do not participate in these priority rules for backward compatibility.
- The message storage cannot be changed while the Milvus system is running.
- Only Kafka 2.x or 3.x verison is supported.
Configure RocksMQ
RocksMQ is the default message storage in Milvus standalone.
Currently, you can only configure RocksMQ as the message storage for Milvus standalone with Milvus Operator.
Example
The following example configures a RocksMQ service.
apiVersion: milvus.io/v1alpha1
kind: Milvus
metadata:
name: milvus
spec:
dependencies: {}
components: {}
config: {}
Configure NATS
NATS is an alternative message storage for NATS.
Example
The following example configures a NATS service.
apiVersion: milvus.io/v1alpha1
kind: Milvus
metadata:
name: milvus
spec:
dependencies:
msgStreamType: 'natsmq'
natsmq:
# server side configuration for natsmq.
server:
# 4222 by default, Port for nats server listening.
port: 4222
# /var/lib/milvus/nats by default, directory to use for JetStream storage of nats.
storeDir: /var/lib/milvus/nats
# (B) 16GB by default, Maximum size of the 'file' storage.
maxFileStore: 17179869184
# (B) 8MB by default, Maximum number of bytes in a message payload.
maxPayload: 8388608
# (B) 64MB by default, Maximum number of bytes buffered for a connection applies to client connections.
maxPending: 67108864
# (√ms) 4s by default, waiting for initialization of natsmq finished.
initializeTimeout: 4000
monitor:
# false by default, If true enable debug log messages.
debug: false
# true by default, If set to false, log without timestamps.
logTime: true
# no log file by default, Log file path relative to.. .
logFile:
# (B) 0, unlimited by default, Size in bytes after the log file rolls over to a new one.
logSizeLimit: 0
retention:
# (min) 3 days by default, Maximum age of any message in the P-channel.
maxAge: 4320
# (B) None by default, How many bytes the single P-channel may contain. Removing oldest messages if the P-channel exceeds this size.
maxBytes:
# None by default, How many message the single P-channel may contain. Removing oldest messages if the P-channel exceeds this limit.
maxMsgs:
components: {}
config: {}
To migrate the message storage from RocksMQ to NATS, do as follows:
Stop all DDL operations.
Call the FlushAll API and then stop Milvus once the API call finishes executing.
Change
msgStreamType
tonatsmq
and make necessary changes to NATS settings inspec.dependencies.natsmq
.Start Milvus again and check whether:
- A log entry that reads
mqType=natsmq
is present in the logs. - A directory named
jetstream
is present in the directory specified inspec.dependencies.natsmq.server.storeDir
.
- A log entry that reads
(Optional) Back up and clean up the data files in the RocksMQ storage directory.
Choose between RocksMQ and NATS?
RockMQ uses CGO to interact with RocksDB and manages the memory by itself, while the pure-GO NATS embedded in the Milvus installation delegates its memory management to Go’s garbage collector (GC).
In the scenario where the data packet is smaller than 64 kb, RocksDB outperforms in terms of memory usage, CPU usage, and response time. On the other hand, if the data packet is greater than 64 kb, NATS excels in terms of response time with sufficient memory and ideal GC scheduling.
Currently, you are advised to use NATS only for experiments.
Configure Pulsar
Pulsar manages logs of recent changes, outputs stream logs, and provides log subscriptions. Configuring Pulsar for message storage is supported in both Milvus standalone and Milvus cluster. However, with Milvus Operator, you can only configure Pulsar as message storage for Milvus cluster. Add required fields under spec.dependencies.pulsar
to configure Pulsar.
pulsar
supports external
and inCluster
.
External Pulsar
external
indicates using an external Pulsar service.
Fields used to configure an external Pulsar service include:
external
: Atrue
value indicates that Milvus uses an external Pulsar service.endpoints
: The endpoints of Pulsar.
Example
The following example configures an external Pulsar service.
apiVersion: milvus.io/v1alpha1
kind: MilvusCluster
metadata:
name: my-release
labels:
app: milvus
spec:
dependencies: # Optional
pulsar: # Optional
# Whether (=true) to use an existed external pulsar as specified in the field endpoints or
# (=false) create a new pulsar inside the same kubernetes cluster for milvus.
external: true # Optional default=false
# The external pulsar endpoints if external=true
endpoints:
- 192.168.1.1:6650
components: {}
config: {}
Internal Pulsar
inCluster
indicates when a Milvus cluster starts, a Pulsar service starts automatically in the cluster.
Example
The following example configures an internal Pulsar service.
apiVersion: milvus.io/v1alpha1
kind: MilvusCluster
metadata:
name: my-release
labels:
app: milvus
spec:
dependencies:
pulsar:
inCluster:
values:
components:
autorecovery: false
zookeeper:
replicaCount: 1
bookkeeper:
replicaCount: 1
resoureces:
limit:
cpu: '4'
memory: 8Gi
requests:
cpu: 200m
memory: 512Mi
broker:
replicaCount: 1
configData:
## Enable `autoSkipNonRecoverableData` since bookkeeper is running
## without persistence
autoSkipNonRecoverableData: "true"
managedLedgerDefaultEnsembleSize: "1"
managedLedgerDefaultWriteQuorum: "1"
managedLedgerDefaultAckQuorum: "1"
proxy:
replicaCount: 1
components: {}
config: {}
pulsar.inCluster.values
as shown in the preceding example.Assuming that the configuration file is named milvuscluster.yaml
, run the following command to apply the configuration.
kubectl apply -f milvuscluster.yaml
Configure Kafka
Pulsar is the default message storage in a Milvus cluster. If you want to use Kafka, add the optional field msgStreamType
to configure Kafka.
kafka
supports external
and inCluster
.
External Kafka
external
indicates using an external Kafka service.
Fields used to configure an external Kafka service include:
external
: Atrue
value indicates that Milvus uses an external Kafka service.brokerList
: The list of brokers to send the messages to.
Example
The following example configures an external Kafka service.
apiVersion: milvus.io/v1alpha1
kind: MilvusCluster
metadata:
name: my-release
labels:
app: milvus
spec:
config:
kafka:
# securityProtocol supports: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL
securityProtocol: PLAINTEXT
# saslMechanisms supports: PLAIN, SCRAM-SHA-256, SCRAM-SHA-512
saslMechanisms: PLAIN
saslUsername: ""
saslPassword: ""
# Omit other fields ...
dependencies:
# Omit other fields ...
msgStreamType: "kafka"
kafka:
external: true
brokerList:
- "kafkaBrokerAddr1:9092"
- "kafkaBrokerAddr2:9092"
# ...
SASL configurations are supported in operator v0.8.5 or higher version.
Internal Kafka
inCluster
indicates when a Milvus cluster starts, a Kafka service starts automatically in the cluster.
Example
The following example configures an internal Kafka service.
apiVersion: milvus.io/v1alpha1
kind: MilvusCluster
metadata:
name: my-release
labels:
app: milvus
spec:
dependencies:
msgStreamType: "kafka"
kafka:
inCluster:
values: {} # values can be found in https://artifacthub.io/packages/helm/bitnami/kafka
components: {}
config: {}
Find the complete configuration items to configure an internal Kafka service here. Add configuration items as needed under kafka.inCluster.values
.
Assuming that the configuration file is named milvuscluster.yaml
, run the following command to apply the configuration.
kubectl apply -f milvuscluster.yaml
What’s next
Learn how to configure other Milvus dependencies with Milvus Operator: