2.2. Configuration

2.2.1. Various Accessor services

2.2.1.1. Accessor-Replicator

Used by remote request from Replicator. It listens to a Topic replicator-action-in from (local) Remote Replicator and is able, through the Local Replicator to access to remote Object if needed for local creation (clone) or to Accessor Internal Service.

This service has no API and only uses a Topic as incoming requests.

2.2.1.2. Accessor-Simple-Gateway

Simple Cloud Storage Gateway without any database and replication nor reconciliation support.

It is means for an easy move from existing storage to Cloud Clone Store, to later on apply the real Accessor service.

For instance the steps could be:

• Add this Simple Gateway in front of an application for existing buckets

• In parallel, import the content of those buckets using the special procedure (see Reconcilitator import from existing Storage) such that all buckets and associated objects are in the CCS database

• Once import done, the Simple Gateway could be shutdown to let the Accessor Server replacing it, while the application still can access to the buckets and associated objects

• When a new site is build, a replication can be setup such that the full services are offer to the application (using Reconciliator for instance special procedure for new and empty replication site or through standard Reconciliator process for an existing (partial or not) remote site)

Note that this version has only Ownership control over deletion of a bucket, not any specific control on other operations such as read, create or delete an object within a bucket.

2.2.1.3. Accessor-Server

Used by application (clients) to interact with Cloud Storage, enabling replication and remote access and reconciliation, using the public API.

It is also used internally by all services when they need to access or interact with buckets and objects, through the internal API, which must be not available to other services than Cloud Clone Store itself.

Note that this version has full Ownership control over deletion of a bucket, but also on other operations such as read, create or delete an object within a bucket from any client.

2.2.2. Client with Apache httpclient5

In order to allow more applications to use Clone Cloud Store, an Apache httpclient 5 based CCS client is also available in ccs-accessor-client-apache.

Dependencies is minimal while all functionalities are supported.

Quarkus is not required.

2.2.3. application.yaml configuration

2.2.3.1. Client configurations

Accessor Cloud Clone Store Client Configuration

Property/Yaml property	Possible Values
quarkus.rest-client."io.clonecloudstore.accessor.client.api.AccessorBucketApi".url	Http(s) url of the service
quarkus.rest-client."io.clonecloudstore.accessor.client.api.AccessorObjectApi".url	Http(s) url of the service

Accessor Cloud Clone Store Internal Client Configuration

Property/Yaml property	Possible Values
quarkus.rest-client."io.clonecloudstore.accessor.client.internal.api.AccessorBucketInternalApi".url	Http(s) url of the service
quarkus.rest-client."io.clonecloudstore.accessor.client.internal.api.AccessorObjectInternalApi".url	Http(s) url of the service

2.2.3.2. Accessor Replicator configuration

Accessor Replicator Cloud Clone Store Service Configuration

Property/Yaml property or Environment variable	Possible Values	Default Value
ccs.accessor.site	Name of the site	unconfigured
ccs.accessor.internal.compression	true or false, True to allow compression between services	false
Redefining mp.messaging.incoming.replicator-action-in or env CCS_REQUEST_ACTION	Name of the incoming topic for Action Requests (if more than 1 instance, add broadcast=true to the configuration)	request-action
quarkus.mongodb.database	Name of the associated database (if MongoDB used, with ccs.db.type = mongo)
quarkus.rest-client."io.clonecloudstore.replicator.client.api.LocalReplicatorApi".url	Http(s) url of the service
quarkus.rest-client."io.clonecloudstore.administration.client.api.OwnershipApi".url	Http(s) url of the service

2.2.3.3. Accessor configuration

Accessor Cloud Clone Store Service Configuration

Property/Yaml property or Environment variable	Possible Values	Default Value
ccs.accessor.site	Name of the site	unconfigured
ccs.accessor.remote.read	true or false, True to allow remote access when object not locally found	false
ccs.accessor.remote.fixOnAbsent	true or false, True to allow to fix using remote accessed object	false
ccs.accessor.internal.compression	true or false, True to allow compression between services	false
Redefining mp.messaging.outgoing.replicator-action-out or env CCS_REQUEST_ACTION	Name of the outgoing topic for Action Requests	request-action
Redefining mp.messaging.outgoing.replicator-request-out or env CCS_REQUEST_REPLICATION	Name of the outgoing topic for Replication Requests	request-replication
quarkus.mongodb.database	Name of the associated database (if MongoDB used, with ccs.db.type = mongo)
quarkus.rest-client."io.clonecloudstore.replicator.client.api.LocalReplicatorApi".url	Http(s) url of the service
quarkus.rest-client."io.clonecloudstore.administration.client.api.OwnershipApi".url	Http(s) url of the service

2.2.3.4. Accessor Simple Gateway configuration

Accessor Simple Gateway Cloud Clone Store Service Configuration

Property/Yaml property	Possible Values	Default Value
ccs.accessor.site	Name of the site	unconfigured

2.2.3.5. Accessor common configuration

For both Accessor Replicator Cloud Clone Store Service and Accessor Cloud Clone Store Service, an extra configuration is needed according to the Storage Driver used:

2.2.3.5.1. Specific Driver configurations

Warning

Note for S3 that maxPartSizeForUnknownLength or driverMaxChunkSize should be defined according to memory available and concurrent access, as each transfer (upload or download) could lead to one buffer of this size for each.

Driver for S3 Service Configuration

Property/Yaml property	Possible Values
ccs.driver.s3.host	S3 Host (do not use quarkus.s3.endpoint-override)
ccs.driver.s3.keyId	S3 KeyId (do not use quarkus.s3.aws.credentials.static-provider.access-key-id nor aws.accessKeyId)
ccs.driver.s3.key	S3 Key (do not use quarkus.s3.aws.credentials.secret-access-key nor aws.secretAccessKey)
ccs.driver.s3.region	S3 Region (do not use quarkus.s3.aws.region)
ccs.driver.s3.maxPartSize	MultiPart size (minimum 5 MB, maximum 5 GB, default 256 MB)
ccs.driver.s3.maxPartSizeForUnknownLength	512 MB as in ccs.driverMaxChunkSize, MultiPart size (minimum 5 MB, maximum ~2 GB): will be used to buffer InputStream if length is unknown, so take care of the Memory consumption associated (512 MB, default, will limit the total InputStream length to 5 TB since 10K parts)

Driver for Azure Blob Storage Service Configuration

Property/Yaml property	Possible Values
quarkus.azure.storage.blob.connection-string	Connection String to Azure Blob Storage (see https://docs.quarkiverse.io/quarkus-azure-services/dev/index.html)
ccs.driver.azure.maxConcurrency	2, Maximum concurrency in upload/download with Azure Blob Storage
ccs.driver.azure.maxPartSize	256 MB, MultiPart size (minimum 5 MB, maximum 4 GB, default 256 MB)
ccs.driver.azure.maxPartSizeForUnknownLength	512 MB as in ccs.driverMaxChunkSize, MultiPart size (minimum 5 MB, maximum ~2 GB): will be used to buffer InputStream if length is unknown (no memory impact)

Driver for Google Cloud Storage Service Configuration

Property/Yaml property	Possible Values
quarkus.google.cloud.project-id	Project Id in Google Cloud (and related Authentication see https://docs.quarkiverse.io/quarkus-google-cloud-services/main/index.html)
ccs.driver.google.disableGzip	true, Default is to use Gzip content, but may be disabled (default: true so disabled)
ccs.driver.google.maxPartSize	256 MB, MultiPart size (minimum 5 MB, maximum 4 GB, default 256 MB) (Property ignored)
ccs.driver.google.maxBufSize	128 MB; MultiPart size (minimum 5 MB, maximum ~2 GB): will be used to buffer InputStream if length is unknown (no memory impact)

Accessor calls Ownership service to check or create ownership for each bucket.

Ownership Cloud Clone Store Client Configuration

Property/Yaml property	Possible Values
quarkus.rest-client."io.clonecloudstore.administration.client.api.OwnershipApi".url	Http(s) url of the service

2.2.3.6. Accessor buffered configuration

For both Accessor Simple Gateway Cloud Clone Store Service and Accessor Cloud Clone Store Service, an extra configuration could be set to allow buffered streams.

Warning

The buffered configuration is intend to protect against non resilient Driver services. But it is at the cost of an extra storage on the Accessor service to store temporarily the uploaded stream, until they are in the Driver final service. This implies to “guess” how many local storage space is needed.

This option should not be activated in general, but allows to handle final Driver service that have a bad resilience, at the price of extra local storage.

The global logic is the following:

• When an upload occurs, the inputStream is first backup into the local filesystem.

• Once backuped, it is then uploaded to the Driver.

• If the Driver upload is in success, the local copy is deleted.

• On the contrary, in case of failure, the local copy remains and is add to an asynchronous retry handler.

  • The related item in database has a READY status, even if not uploaded in Driver service

When an access is tried on a Driver Object, the global logic is the following:

• If the Driver access is in error, there is an extra try using the local filesystem

When a delete occurs on a Driver Object, there is a try to delete also from the local filesystem.

Warning

When having multiple instances of Accessor, if one wants to not rely on which server the call occurs, one can share the extra storage (using NFS for instance). If not, access and delete will not benefit other instances.

The filesystem is as much as possible guard to prevent no more space on device:

• An option specifies how much space in GB must be available for any upload

• If the upload inputStream size is known, the size is compared to the available space

• In any case where the filesystem is not enough, the local copy will be skipped, therefore relying only on the Driver availability

Warning

This protection can prevent buffered operations due to the lack of space. In this case, the upload relies only on the Driver availability, which is the default behavior.

For any buffered and not yet store to Driver service items, there is an extra backgroung task that will take them in consideration. The schedule is every ccs.accessor.store.schedule.delay.

• The background task check first if any item shall be uploaded to the Driver

  • It checks the availability in the database (status) and the availability of the Driver service and the item is still missing

  • If everything is OK, it uploads the item and then delete locally the item

  • On the contrary

    • If the item is already in the Driver, it is deleted

    • If the item is not in the Driver, it is reset to the next schedule

• Once all scheduled tasks are over

  • It checks too old items and clean them according to the purge.retention_seconds` configuration

    • For each item, the associated entry status in database is placed as ERR_UPL`

  • Important note: once purged, the items cannot be uploaded anymore automatically

Warning

Most of the normal behaviors of Driver are respected using the buffered space, except listing, streaming of StorageObjects and test of existence of a directory (object is checked but not directory).

Buffered upload Cloud Clone Store Service Configuration

Property/Yaml property	Possible Values	Default Value
ccs.accessor.store.active	true / false	false and should be used with caution
ccs.accessor.store.path	Path to the root for the local store	Temp directory according to io.java.tmpdir (/CCS will be added)
ccs.accessor.store.min_space_gb	integer as number of GB	5 GB by default, should be set according to average upload sizes and duration of unavailability of Driver final service
ccs.accessor.store.purge.retention_seconds	delay in seconds before purge	3600 seconds (1 hour) by default, should be set according to space on local storage
ccs.accessor.store.schedule.delay	delay in duration format (“10s”, “1m”…), a number will be considered in seconds by default	“10s” (10 seconds) by default, should be set according to space on local storage, upload frequency and Driver service stability