Package server configures and launches http/rpc server and storage engines specific to the type of DVID platform: local (e.g., running on MacBook Pro), clustered, or using cloud-based services like Google Cloud.
Datatypes can use any of the three tiers of storage (MetaData, Mutable, Immutable) that provide a layer of storage semantics (latency, mutability, etc) on top of underlying storage engines.
The DVID web client is also managed from this package. For a DVID web console, see the repo:
The goal of a DVID web console is to provide a GUI for monitoring and performing a subset of operations in a nicely formatted view.
DVID command line interaction occurs via the rpc interface to a running server. Please see the main DVID documentation:
const ( // DefaultWebAddress is the default URL of the DVID web server DefaultWebAddress = "localhost:8000" // DefaultRPCAddress is the default RPC address for command-line use of a remote DVID server DefaultRPCAddress = "localhost:8001" // ErrorLogFilename is the name of the server error log, stored in the datastore directory. ErrorLogFilename = "dvid-errors.log" )
const ( // WebAPIVersion is the string version of the API. Once DVID is somewhat stable, // this will be "v1/", "v2/", etc. WebAPIVersion = "" // WebAPIPath is the relative URL path to our Level 2 REST API WebAPIPath = "/api/" + WebAPIVersion // WriteTimeout is the maximum time in seconds DVID will wait to write data down HTTP connection. WriteTimeout = 600 * time.Second // ReadTimeout is the maximum time in seconds DVID will wait to read data from HTTP connection. ReadTimeout = 600 * time.Second )
var ( // MaxDataRequest sets the limit on the amount of data that could be returned for a request MaxDataRequest = int64(3) * dvid.Giga // InteractiveOpsPer2Min gives the number of interactive-level requests // received over the last 2 minutes. This is useful for throttling "batch" // operations on a single DVID server. Note that this metric is an lower // bound on the number of interactive requests over the last minute since // we do non-blocking reports. InteractiveOpsPer2Min int // ActiveHandlers is maximum number of active handlers over last second. ActiveHandlers int // MaxChunkHandlers sets the maximum number of chunk handlers (goroutines) that // can be multiplexed onto available cores. (See -numcpu setting in dvid.go) MaxChunkHandlers = runtime.NumCPU() // HandlerToken is buffered channel to limit spawning of goroutines. // See ProcessChunk() in datatype/imageblk for example. HandlerToken = make(chan int, MaxChunkHandlers) // LargeMutationMutex is a global lock for compute-intense processes that want to // spawn goroutines that consume handler tokens. This lets processes capture most // if not all available handler tokens in a FIFO basis rather than have multiple // concurrent requests launch a few goroutines each. LargeMutationMutex sync.Mutex // TimeoutSecs specifies the seconds waiting to open a datastore for exclusive access. TimeoutSecs int )
var ( // DefaultHost is the default most understandable alias for this server. DefaultHost = "localhost" )
About returns a chart of version identifiers for the DVID source code, DVID datastore, and all component data types for this executable.
AboutJSON returns a JSON string describing the properties of this server.
BadAPIRequest writes a standard error message to http.ResponseWriter for a badly formatted API call.
BadRequest writes an error message out to the http.ResponseWriter using format similar to fmt.Printf.
BlockOnInteractiveRequests will block this goroutine until the number of interactive requests dips below InteractiveOpsBeforeBlock in server configuration.
CacheSize returns the number oF bytes reserved for the given identifier. If unset, will return 0.
CloseTest shuts down server for testing.
CreateTestInstance posts a new data instance for testing.
CreateTestReplaceSync replaces syncs for a given data instance / uuid.
CreateTestSync posts new syncs for a given data instance / uuid.
DatastoreConfig returns data instance configuration necessary to handle id generation.
DecodeJSON decodes JSON passed in a request into a dvid.Config.
GetBackend returns a backend from current configuration.
GitVersion returns a git-derived string that allows recovery of the exact source code used for this DVID server.
GotInteractiveRequest can be called to track the # of interactive requests that require some amount of computation. Don't use this to track simple polling APIs. This routine will not block.
Host returns the most understandable host alias + any port.
Initialize sets up the server (runs webhook, kafka goroutine, etc) and presumes that LoadConfig() or another method was already used to configure the server.
KafkaAvailable returns true if kafka servers are initialized.
LoadConfig loads DVID server configuration from a TOML file.
LogMutation logs a HTTP mutation request to the mutation log specific in the config.
OpenTest initializes the server for testing, setting up caching, datastore, etc. Later configurations will override earlier ones.
SendRPC sends a request to a remote DVID.
Serve starts HTTP and RPC servers.
ServeSingleHTTP fulfills one request using the default web Mux.
SetFullWrite allows mutations on any version.
SetReadOnly can put the server in a read-only mode.
Shutdown handles graceful cleanup of server functions before exiting DVID. This may not be so graceful if the chunk handler uses cgo since the interrupt may be caught during cgo execution.
TestBadHTTP expects a HTTP response with an error status code.
TestHTTP returns the response body bytes for a test request, making sure any response has status OK.
TestHTTPError returns the response body bytes for a test request, making sure any response has status OK.
TestHTTPResponse returns a response from a test run of the DVID server. Use TestHTTP if you just want the response body bytes.
ThrottledHTTP checks if a request can continue under throttling. If so, it returns false. If it cannot (throttled state), it sends a http.StatusServiceUnavailable and returns true. Throttling is controlled by
ThrottledOpDone marks the end of a throttled operation, allowing another op blocked by ThrottledHTTP() to succeed.
WebServer returns the configured host name from TOML file or, if not specified, the retrieved hostname plus the port of the web server.
MutationsConfig specifies handling of mutation logs, which are composed of an append-only logs of mutations for each version and one log for repository changes. A blobstore must also be specified to hold large mutation data that is
TestConfig specifies configuration for testing servers.