Cluster configuration » History » Revision 25
Revision 24 (Tom Clegg, 01/23/2019 08:40 PM) → Revision 25/33 (Eric Biagiotti, 02/01/2019 09:18 PM)
h1. Cluster configuration We are (2019) consolidating configuration from per-microservice yaml/json/ini files into a single cluster configuration document that is used by all components. * Long term: system nodes automatically keep their configs synchronized (using something like consul). * Short term: sysadmin uses tools like puppet and terraform to ensure /etc/arvados/config.yml is identical on all system nodes. * Hosts without config files (e.g., hosts outside the cluster) can retrieve the config document from the API server. h2. Discovery document Previously, we copied selected config values from the API server config into the API discovery document so clients could see them. When clients can get the configuration document itself, this won't be needed. The discovery document should advertise APIs provided by the server, not cluster configuration. h2. Secrets Secrets like BlobSigningKey can be given literally in the config file (convenient for dev/test, consul-template, etc) or indirectly using a secret backend. Anticipated backends: * <code class="yaml">BlobSigningKey: foobar</code> ⇒ the secret is literally <code>foobar</code> * <code class="yaml">BlobSigningKey: "vault:foobar"</code> ⇒ the secret can be obtained from vault using the vault key "foobar" * <code class="yaml">BlobSigningKey: "file:/foobar"</code> ⇒ the secret can be read from the local file @/foobar@ * <code class="yaml">BlobSigningKey: "env:FOOBAR"</code> ⇒ the secret can be read from the environment variable @FOOBAR@ h2. Instructions for ops Tentative instructions for switching config file format/location: # Upgrade Arvados to a version that supports loading all configs from the new cluster-wide config file (maybe 1.4). When services come back up, they will still use your old configuration files, but they will log some deprecation warnings. # Migrate your configuration to the new config file, one component at a time. For each component: ## Restart the component. ## Inspect the deprecation warning that is logged at startup. It will tell you either "old config file is superfluous" or "new config file is incomplete". ## If your old config file is superfluous, delete it. You're done. ## Run the component with the "--config-diff" flag. This suggests changes to your new config file which will make your old config file obsolete. (Alternatively, run the component with the "--config-dump" flag. This outputs a new config file that would make your old config file obsolete. Saving this might be easier than applying a diff, but it will reorder keys and lose comments.) ## Make the suggested changes. ## Repeat until finished. # Upgrade to a version that doesn't support old config files at all (maybe 1.5). h2. Implementation Development strategy for facilitating the above ops instructions: # Read the new config file into an internal struct, if the new config file exists. # Copy old config file values into the new config struct. # Use the new config struct internally (the old config is no longer referenced except in the load-and-copy-to-new-struct step). # Add a mechanism for showing the effect of the old config file on the resulting config struct (see "--config-diff" above). # At startup, if the old config has any effect (i.e., some parts haven't been migrated to the new config file by the operator), log a deprecation warning recommending "--config-diff" and RTFM. # Wait one minor version release cycle. # Error out if the new config file does not exist. # Error out if the old config file exists (...and some parts of the old config are not redundant [optional?]). h2. Example config file (Format not yet frozen!) Notes: * Keys are CamelCase — except in special cases like PostgreSQL connection settings, which are passed through to another system without being interpreted by Arvados. * Arrays and lists are not permitted. These cannot be expressed natively in consul, and tend to be troublesome anyway: "what changed?" is harder to answer usefully, significance of duplicate elements is unclear, etc. <pre><code class="yaml"> Clusters: xyzzy: ManagementToken: eec1999ccb6d75840a2c09bc70b6d3cbc990744e BlobSigningKey: ungu355able BlobSignatureTTL: 172800 SessionKey: 186005aa54cab1ca95a3738e6e954e0a35a96d3d13a8ea541f4156e8d067b4f3 PostgreSQL: ConnectionPool: 32 # max concurrent connections per arvados server daemon Connection: # All parameters here are passed to the PG client library in a connection string; # see https://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-PARAMKEYWORDS Host: localhost Port: 5432 User: arvados Password: s3cr3t DBName: arvados_production client_encoding: utf8 fallback_application_name: arvados HTTPRequestTimeout: 5m Defaults: CollectionReplication: 2 TrashLifetime: 2w UserActivation: ActivateNewUsers: true AutoAdminUser: root@example.com UserProfileNotificationAddress: notify@example.com NewUserNotificationRecipients: {} NewInactiveUserNotificationRecipients: {} RequestLimits: MaxRequestLogParamsSize: 2KB MaxRequestSize: 128MiB MaxIndexDatabaseRead: 128MiB MaxItemsPerResponse: 1000 MultiClusterRequestConcurrency: 4 LogLevel: info CloudVMs: BootProbeCommand: "docker ps -q" SSHPort: 22 SyncInterval: 1m # how often to get list of active instances from cloud provider TimeoutIdle: 1m # shutdown if idle longer than this TimeoutBooting: 10m # shutdown if exists longer than this without running BootProbeCommand successfully TimeoutProbe: 2m # shutdown if (after booting) communication fails longer than this, even if ctrs are running TimeoutShutdown: 1m # shutdown again if node still exists this long after shutdown Driver: Amazon DriverParameters: Region: us-east-1 APITimeout: 20s AWSAccessKeyID: abcdef AWSSecretAccessKey: abcdefghijklmnopqrstuvwxyz ImageID: ami-0a01b48b88d14541e SubnetID: subnet-24f5ae62 SecurityGroups: sg-3ec53e2a AuditLogs: MaxAge: 2w DeleteBatchSize: 100000 UnloggedAttributes: {} # example: {"manifest_text": true} ContainerLogStream: BatchSize: 4KiB BatchTime: 1s ThrottlePeriod: 1m ThrottleThresholdSize: 64KiB ThrottleThresholdLines: 1024 TruncateSize: 64MiB PartialLineThrottlePeriod: 5s Timers: TrashSweepInterval: 60s ContainerDispatchPollInterval: 10s APIRequestTimeout: 20s Scaling: MaxComputeNodes: 64 EnablePreemptibleInstances: false DisableAPIMethods: {} # example: {"jobs.create": true} DockerImageFormats: {"v2": true} Crunch1: Enable: true CrunchJobWrapper: none CrunchJobUser: crunch CrunchRefreshTrigger: /tmp/crunch_refresh_trigger DefaultDockerImage: false NodeProfiles: # Key is a profile name; can be specified on service prog command line, defaults to $(hostname) keep: # Don’t run other services automatically -- only specified ones Default: {Disable: true} Keepstore: {Listen: ":25107"} apiserver: Default: {Disable: true} RailsAPI: {Listen: ":9000", TLS: true} Controller: {Listen: ":9100"} Websocket: {Listen: ":9101"} Health: {Listen: ":9199"} keep: Default: {Disable: true} KeepProxy: {Listen: ":9102"} KeepWeb: {Listen: ":9103"} *: # This section used for a node whose profile name is not listed above Default: {Disable: false} # (this is the default behavior) Volumes: xyzzy-keep-0: Type: s3 Region: us-east Bucket: xyzzy-keep-0 # [rest of keepstore volume config goes here] WebRoutes: # “default” means route according to method/host/path (e.g., if host is a login shell, route there) xyzzy.arvadosapi.com: default # “collections” means always route to keep-web collections.xyzzy.arvadosapi.com: collections # leading * is a wildcard (longest match wins) "*--collections.xyzzy.arvadosapi.com": collections cloud.curoverse.com: workbench workbench.xyzzy.arvadosapi.com: workbench "*.xyzzy.arvadosapi.com": default InstanceTypes: m4.large: VCPUs: 2 RAM: 8000000000 Scratch: 31000000000 Price: 0.1 m4.large-1t: # same instance type as m4.large but our scripts attach more scratch ProviderType: m4.large VCPUs: 2 RAM: 8000000000 Scratch: 999000000000 Price: 0.12 m4.xlarge: VCPUs: 4 RAM: 16000000000 Scratch: 78000000000 Price: 0.2 m4.8xlarge: VCPUs: 40 RAM: 160000000000 Scratch: 156000000000 Price: 2 m4.16xlarge: VCPUs: 64 RAM: 256000000000 Scratch: 310000000000 Price: 3.2 c4.large: VCPUs: 2 RAM: 3750000000 Price: 0.1 c4.8xlarge: VCPUs: 36 RAM: 60000000000 Price: 1.591 RemoteClusters: xrrrr: Host: xrrrr.arvadosapi.com Proxy: true # proxy requests to xrrrr on behalf of our clients AuthProvider: true # users authenticated by xrrrr can use our cluster </code></pre> h2. Go Configuration Framework Options Viper and go-config seem to be the leading go config framework contenders considering some of our long term goals (config synchronization); but viper seems to be the more widely adopted of the two. *spf13/viper:* https://github.com/spf13/viper *micro/go-config* https://github.com/micro/go-config - more useful - https://micro.mu/docs/go-config.html Both solutions are very similar in terms of reported functionality. Both have watch support, and would allow for merging flags, environment variables, remote key stores (Consul), and our master YAML config. Viper also supports encrypted remote key/value access.