CHANGELOG.md

Changelog

This changelog documents all notable user-facing changes of VAST.

Unreleased

• 🐞 A race condition during server shutdown could lead to an invariant violation, resulting in a firing assertion. Streamlining the shutdown logic resolved the issue. #1473

• 🐞 Insufficient permissions for one of the paths in the schema-dirs option would lead to a crash in vast start. #1472

• 🐞 A query for a field or field name suffix that matches multiple fields of different types would erroneously return no results. #1447

• ⚠️ The default size of table slices (event batches) that is created from vast import processes has been changed from 1000 to 1024. #1396

• 🐞 The disk monitor now correctly erases partition synopses from the meta index. #1450

• 🐞 The archive, index, source, and sink components now report metrics while idle instead of omitting them entirely. This allows for distinguishing between idle and not running components from the metrics. #1451

• 🐞 VAST no longer crashes when the disk monitor tries to calculate the size of the database while files are being deleted. Instead, it will retry after the configured scan interval. #1458

• ⚡️ A new VASTRegisterPlugin CMake function enables easy setup of the build scaffolding required for plugins. Plugins can now be linked statically against VAST. Configure with --with-static-plugins or build a static binary to link all plugins built alongside VAST statically. All plugin build scaffoldings must be adapted, older plugins do no longer work. #1445 #1452

• ⚠️ The type extractor in the expression language now includes aliased types. For example, given the type definition for port from the base schema type port = count, a search for :count will consider fields of type port. #1446

• ⚠️ The time to first response of queries that compare a concept to a string has been reduced noticably. In the particular case of large databases containing many different event types and queries with a high selectivity we were able to measure speedups of up to 5x. #1433

• 🐞 The JSON parser now accepts data with numerical or boolean values in fields that expect strings according the schema. #1439

• 🐞 Data that was ingested before the deprecation of the #timestamp attribute wasn't exported correctly with newer versions. This is now corrected. #1432

• ⚠️ The zeek-to-vast relay utility was moved to the tenzir/zeek-vast repository. All options related to zeek-to-vast and the bundled Broker submodule were removed. #1435

• 🎁 VAST now supports nested records in Arrow table slices and in the JSON import, e.g., data of type list<record<name: string, age: count>. While nested record fields are not yet queryable, ingesting such data will no longer cause VAST to crash. MessagePack table slices don't support records in lists yet. #1429

• 🐞 Some non-null pointers were incorrectly rendered as *nullptr in log messages. #1430

• 🎁 The schema language now supports 4 operations on record types: + combines the fields of 2 records into a new record. <+ and +> are variations of + that give precedence to the left and right operand respectively. - creates a record with the field specified as its right operand removed. #1407

• ⚠️ The option vast.no-default-schema is deprecated, as it is no longer needed to override types from bundled schemas. #1409

• ⚠️ VAST now ships with schema record types for Suricata's mqtt and anomaly event types. #1408 @satta

• ⚡️ The previously deprecated #timestamp extractor has been removed from the query language entirely. #1399

2021.02.24

⚡️ Breaking Changes

• The previously deprecated options vast.spawn.importer.ids and vast.schema-paths no longer work. Furthermore, queries spread over multiple arguments are now disallowed instead of triggering a deprecation warning. #1374

• The special meaning of the #timestamp attribute has been removed from the schema language. Timestamps can from now on be marked as such by using the timestamp type instead. Queries of the form #timestamp <op> value remain operational but are deprecated in favor of :timestamp. Note that this change also affects :time queries, which aren't supersets of #timestamp queries any longer. #1388

• All options in vast.metrics.* had underscores in their names replaced with dashes to align with other options. For example, vast.metrics.file_sink is now vast.metrics.file-sink. The old options no longer work. #1368

• User-supplied schema files are now picked up from <SYSCONFDIR>/vast/schema and <XDG_CONFIG_HOME>/vast/schema instead of <XDG_DATA_HOME>/vast/schema. #1372

• VAST now requires {fmt} >= 5.2.1 to be installed. #1330

• VAST switched to spdlog >= 1.5.0 for logging. For users, this means: The vast.console-format and vast.file-format now must be specified using the spdlog pattern syntax as described here. All settings under caf.logger.* are now ignored by VAST, and only the vast.* counterparts are used for logger configuration. #1223 #1328 #1334 #1390 @a4z

⚠️ Changes

• The output of vast help and vast documentation now goes to stdout instead of to stderr. Erroneous invocations of vast also print the helptext, but in this case the output still goes to stderr to avoid interference with downstream tooling. #1385

• The query normalizer interprets value predicates of type subnet more broadly: given a subnet S, the parser expands this to the expression :subnet == S || :addr in S. This change makes it easier to search for IP addresses belonging to a specific subnet. #1373

• The infer command has an improved heuristic for the number types int, count, and real. #1343 #1356 @ngrodzitski

• The options listen, read, schema, schema-file, type, and uds can from now on be supplied to the import command directly. Similarly, the options write and uds can be supplied to the export command. All options can still be used after the format subcommand, but that usage is deprecated. #1354

• Schema parsing now uses a 2-pass loading phase so that type aliases can reference other types that are later defined in the same directory. Additionally, type definitions from already parsed schema dirs can be referenced from schema types that are parsed later. Types can also be redefined in later directories, but a type can not be defined twice in the same directory. #1331

🧬 Experimental Features

• Sigma rules are now a valid format to represent query expression. VAST parses the detection attribute of a rule and translates it into a native query expression. To run a query using a Sigma rule, pass it on standard input, e.g., vast export json < rule.yaml. #1379

🎁 Features

• The type extractor in the expression language now works with user defined types. For example the type port is defined as type port = count in the base schema. This type can now be queried with an expression like :port == 80. #1382

• The new options vast.metrics.file-sink.real-time and vast.metrics.uds-sink.real-time enable real-time metrics reporting for the file sink and UDS sink respectively. #1368

• The meta index now stores partition synopses in separate files. This will decrease restart times for systems with large databases, slow disks and aggressive readahead settings. A new config setting vast.meta-index-dir allows storing the meta index information in a separate directory. #1330 #1376

• The JSON import now always relies upon simdjson. The previously experimental --simdjson option to the vast import json|suricata|zeek-json commands no longer exist as the feature is considered stable. #1343 #1356 @ngrodzitski

• VAST rotates server logs by default. The new config options vast.disable-log-rotation and vast.log-rotation-threshold can be used to control this behaviour. #1223 #1362

🐞 Bug Fixes

• A bug in the new simdjson based JSON reader introduced in #1356 could trigger an assertion in the vast import process if an input field could not be converted to the field type in the target layout. This is no longer the case. #1386

• An ordering issue introduced in #1295 that could lead to a segfault with long-running queries was reverted. #1381

2021.01.28

⚡️ Breaking Changes

• The GitHub CI changed to Debian Buster and produces Debian artifacts instead of Ubuntu artifacts. Similarly, the Docker images we provide on dockerhub use Debian Buster as base image. To build Docker images locally, users must set DOCKER_BUILDKIT=1 in the build environment. #1294

• The new short options -v, -vv, -vvv, -q, -qq, and -qqq map onto the existing verbosity levels. The existing short syntax, e.g., -v debug, no longer works. #1244

⚠️ Changes

• The option vast.schema-paths is renamed to vast.schema-dirs. The old option is deprecated and will be removed in a future release. #1287

• VAST preserves nested JSON objects in events instead of formatting them in a flattened form when exporting data with vast export json. The old behavior can be enabled with vast export json --flatten. #1257 #1289

• vast start prints the endpoint it is listening on when providing the option --print-endpoint. #1271

🧬 Experimental Features

• VAST relies on simdjson for JSON parsing. The substantial gains in throughput shift the bottleneck of the ingest path from parsing input to indexing at the node. To use the (yet experimental) feature, use vast import json|suricata|zeek-json --simdjson. #1230 #1246 #1281 #1314 #1315 @ngrodzitski

• VAST features a new plugin framework to support efficient customization points at various places of the data processing pipeline. There exist several base classes that define an interface, e.g., for adding new commands or spawning a new actor that processes the incoming stream of data. The directory examples/plugins/example contains an example plugin. #1208 #1264 #1275 #1282 #1285 #1287 #1302 #1307 #1316

🎁 Features

• The output of vast status contains detailed memory usage information about active and cached partitions. #1297

• VAST installations bundle a LICENSE.3rdparty file alongside the regular LICENSE file that lists all embedded code that is under a separate license. #1306

• VAST queries also accept nanoseconds, microseconds, milliseconds seconds and minutes as units for a duration. #1265

• The new import zeek-json command allows for importing line-delimited Zeek JSON logs as produced by the json-streaming-logs package. Unlike stock Zeek JSON logs, where one file contains exactly one log type, the streaming format contains different log event types in a single stream and uses an additional _path field to disambiguate the log type. For stock Zeek JSON logs, use the existing import json with the -t flag to specify the log type. #1259

🐞 Bug Fixes

• A potential race condition that could lead to a hanging export if a partition was persisted just as it was scanned no longer exists. #1295

• Disk monitor quota settings not ending in a 'B' are no longer silently discarded. #1278

• Line based imports correctly handle read timeouts that occur in the middle of a line. #1276

• For relocatable installations, the list of schema loading paths does not include a build-time configured path any more. #1249

• Values in JSON fields that can't be converted to the type that is specified in the schema won't cause the containing event to be dropped any longer. #1250

• Invalid Arrow table slices read from disk no longer trigger a segmentation fault. Instead, the invalid on-disk state is ignored. #1247

• Manually specified configuration files may reside in the default location directories. Configuration files can be symlinked. #1248

2020.12.16

⚡️ Breaking Changes

• The build configuration of VAST received a major overhaul. Inclusion of libvast in other procects via add_subdirectory(path/to/vast) is now easily possible. The names of all build options were aligned, and the new build summary shows all available options. #1175

• The port type is no longer a first-class type. The new way to represent transport-layer ports relies on count instead. In the schema, VAST ships with a new alias type port = count to keep existing schema definitions in tact. However, this is a breaking change because the on-disk format and Arrow data representation changed. Queries with :port type extractors no longer work. Similarly, the syntax 53/udp no longer exists; use count syntax 53 instead. Since most port occurrences do not carry a known transport-layer type, and the type information exists typically in a separate field, removing port as native type streamlines the data model. #1187

• Archive segments no longer include an additional, unnecessary version identifier. We took the opportunity to clean this up bundled with the other recent breaking changes. #1168

• The on-disk format for table slices now supports versioning of table slice encodings. This breaking change makes it so that adding further encodings or adding new versions of existing encodings is possible without breaking again in the future. #1143 #1157 #1160 #1165

• CAF-encoded table slices no longer exist. As such, the option vast.import.batch-encoding now only supports arrow and msgpack as arguments. #1142

• The splunk-to-vast script has a new name: taxonomize. The script now also generates taxonomy declarations for Azure Sentinel. #1134

⚠️ Changes

• The zeek export format now strips off the prefix zeek. to ensure full compatibility with regular Zeek output. For all non-Zeek types, the prefix remains intact. #1205

• Installed schema definitions now reside in <datadir>/vast/schema/types, taxonomy definitions in <datadir>/vast/schema/taxonomy, and concept definitions in <datadir/vast/schema/concepts, as opposed to them all being in the schema directory directly. When overriding an existing installation, you may have to delete the old schema definitions by hand. #1194

• The Suricata schemas received an overhaul: there now exist vlan and in_iface fields in all types. In addition, VAST ships with new types for ikev2, nfs, snmp, tftp, rdp, sip and dcerpc. The tls type gets support for the additional sni and session_resumed fields. #1237 #1176 #1180 #1186 @satta

• VAST now listens on port 42000 instead of letting the operating system choose the port if the option vast.endpoint specifies an endpoint without a port. To restore the old behavior, set the port to 0 explicitly. #1170

• The default segment size in the archive is now 1 GiB. This reduces fragmentation of the archive meta data and speeds up VAST startup time. #1166

• VAST now processes the schema directory recursively, as opposed to stopping at nested directories. #1154

• VAST does not produce metrics by default any more. The option --disable-metrics has been renamed to --enable-metrics accordingly. #1137

• VAST no longer requires you to manually remove a stale PID file from a no-longer running vast process. Instead, VAST prints a warning and overwrites the old PID file. #1128

🧬 Experimental Features

• The expression language gained support for the #field meta extractor. It is the complement for #type and uses suffix matching for field names at the layout level. #1228

• The query language now supports models. Models combine a list of concepts into a semantic unit that can be fulfiled by an event. If the type of an event contains a field for every concept in a model. Turn to the documentation for more information. #1185 #1228

• VAST now ships with its own taxonomy and basic concept definitions for Suricata, Zeek, and Sysmon. #1135 #1150

🎁 Features

• Low-selectivity queries of string (in)equality queries now run up to 30x faster, thanks to more intelligent selection of relevant index partitions. #1214

• On Linux, VAST now contains a set of built-in USDT tracepoints that can be used by tools like perf or bpftrace when debugging. Initially, we provide the two tracepoints chunk_make and chunk_destroy, which trigger every time a vast::chunk is created or destroyed. #1206

• The new dump command prints configuration and schema-related information. The implementation allows for printing all registered concepts and models, via vast dump concepts and vast dump models. The flag to --yaml to dump switches from JSON to YAML output, such that it confirms to the taxonomy configuration syntax. #1196 #1233

• A new key 'meta-index-bytes' appears in the status output generated by vast status --detailed. #1193

• The storage required for index IP addresses has been optimized. This should result in significantly reduced memory usage over time, as well as faster restart times and reduced disk space requirements. #1172 #1200 #1216

• The new option --print-bytesizes of lsvast prints information about the size of certain fields of the flatbuffers inside a VAST database directory. #1149

• The new option vast.client-log-file enables client-side logging. By default, VAST only writes log files for the server process. #1132

🐞 Bug Fixes

• Concepts that reference other concepts are now loaded correctly from their definition. #1236

• The vast status command does not collect status information from sources and sinks any longer. They were often too busy to respond, leading to a long delay before the command completed. #1234

• The summary log message of vast export now contains the correct number of candidate events. #1228

• The index no longer causes exporters to deadlock when the meta index produces false positives. #1225

• The index now correctly drops further results when queries finish early, thus improving the performance of queries for a limited number of events. #1209

• The index no longer crashes when too many parallel queries are running. #1210

• The type registry now detects and handles breaking changes in schemas, e.g., when a field type changes or a field is dropped from record. #1195

• VAST no longer blocks when an invalid query operation is issued. #1189

• vast import no longer stalls when it doesn't receive any data for more than 10 seconds. #1136

• The output of vast status --detailed now contains informations about runnings sinks, e.g., vast export <format> <query> processes. #1155

• The vast.yaml.example contained syntax errors. The example config file now works again. #1145

• VAST no longer starts if the specified config file does not exist. #1147

2020.10.29

⚠️ Changes

• The default database directory moved to /var/lib/vast for Linux deployments. #1116

• Log files are now less verbose because class and function names are not printed on every line. #1107

• The new option import.read-timeout allows for setting an input timeout for low volume sources. Reaching the timeout causes the current batch to be forwarded immediately. This behavior was previously controlled by import.batch-timeout, which now only controls the maximum buffer time before the source forwards batches to the server. #1096

• VAST will now warn if a client command connects to a server that runs on a different version of the vast binary. #1098

🧬 Experimental Features

• A new disk monitor component can now monitor the database size and delete data that exceeds a specified threshold. Once VAST reaches the maximum amount of disk space, the disk monitor deletes the oldest data. The command-line options --disk-quota-high, --disk-quota-low, and --disk-quota-check-interval control the rotation behavior. #1103

• The query language now comes with support for concepts, the first part of taxonomies. Concepts is a mechanism to unify the various naming schemes of different data formats into a single, coherent nomenclature. #1102

🎁 Features

• The expression language now accepts records without field names. For example,id == <192.168.0.1, 41824, 143.51.53.13, 25, "tcp"> is now valid syntax and instantiates a record with 5 fields. Note: expressions with records currently do not execute. #1129

• The new options vast.segments and vast.max-segment-size control how the archive generates segments. #1103

• The new script splunk-to-vast converts a splunk CIM model file in JSON to a VAST taxonomy. For example, splunk-to-vast < Network_Traffic.json renders the concept definitions for the Network Traffic datamodel. The generated taxonomy does not include field definitions, which users should add separately according to their data formats. #1121

• When running VAST under systemd supervision, it is now possible to use the Type=notify directive in the unit file to let VAST notify the service manager when it becomes ready. #1091

🐞 Bug Fixes

• The lsvast tool failed to print FlatBuffers schemas correctly. The output now renders correctly. #1123

• VAST no longer opens a random public port, which used to be enabled in the experimental VAST cluster mode in order to transparently establish a full mesh. #1110

• The vast status --detailed command now correctly shows the status of all sources, i.e., vast import or vast spawn source commands. #1109

• Sources that receive no or very little input do not block vast status any longer. #1096

• The lookup for schema directories now happens in a fixed order. #1086

2020.09.30

⚡️ Breaking Changes

• Data exported in the Apache Arrow format now contains the name of the payload record type in the metadata section of the schema. #1072

• The persistent storage format of the index now uses FlatBuffers. #863

⚠️ Changes

• All configuration options are now grouped into vast and caf sections, depending on whether they affect VAST itself or are handed through to the underlying actor framework CAF directly. Take a look at the bundled vast.yaml.example file for an explanation of the new layout. #1073

• We refactored the index architecture to improve stability and responsiveness. This includes fixes for several shutdown issues. #863

• The options that affect batches in the import command received new, more user-facing names: import.table-slice-type, import.table-slice-size, and import.read-timeout are now called import.batch-encoding, import.batch-size, and import.read-timeout respectively. #1058

• The prioprietary VAST configuration file has changed to the more ops-friendly industry standard YAML. This change introduced also a new dependency: yaml-cpp version 0.6.2 or greater. The top-level vast.yaml.example illustrates how the new YAML config looks like. Please rename existing configuration files from vast.conf to vast.yaml. VAST still reads vast.conf but will soon only look for vast.yaml or vast.yml files in available configuration file paths. #1045 #1055 #1059 #1062

• The global VAST configuration now always resides in <sysconfdir>/vast/vast.conf, and bundled schemas always in <datadir>/vast/schema/. VAST no longer supports reading a vast.conf file in the current working directory. #1036

• The JSON export format now renders duration and port fields using strings as opposed to numbers. This avoids a possible loss of information and enables users to re-use the output in follow-up queries directly. #1034

• The delay between the periodic log messages for reporting the current event rates has been increased to 10 seconds. #1035

🧬 Experimental Features

• The vast get command has been added. It retrieves events from the database directly by their ids. #938

🎁 Features

• VAST now ships with a new tool lsvast to display information about the contents of a VAST database directory. See lsvast --help for usage instructions. #863

• VAST now merges the contents of all used configuration files instead of using only the most user-specific file. The file specified using --config takes the highest precedence, followed by the user-specific path ${XDG_CONFIG_HOME:-${HOME}/.config}/vast/vast.conf, and the compile-time path <sysconfdir>/vast/vast.conf. #1040

• The output of the status command was restructured with a strong focus on usability. The new flags --detailed and --debug add additional content to the output. #995

• VAST now supports the XDG base directory specification: The vast.conf is now found at ${XDG_CONFIG_HOME:-${HOME}/.config}/vast/vast.conf, and schema files at ${XDG_DATA_HOME:-${HOME}/.local/share}/vast/schema/. The user-specific configuration file takes precedence over the global configuration file in <sysconfdir>/vast/vast.conf. #1036

🐞 Bug Fixes

• 🐞 Stalled sources that were unable to generate new events no longer stop import processes from shutting down under rare circumstances. #1058

2020.08.28

⚡️ Breaking Changes

• We now bundle a patched version of CAF, with a changed ABI. This means that if you're linking against the bundled CAF library, you also need to distribute that library so that VAST can use it at runtime. The versions are API compatible so linking against a system version of CAF is still possible and supported. #1020

⚠️ Changes

• The vector type has been renamed to list. In an effort to streamline the type system vocabulary, we favor list over vector because it's closer to existing terminology (e.g., Apache Arrow). This change requires updating existing schemas by changing vector<T> to list<T>. #1016

• The set type has been removed. Experience with the data model showed that there is no strong use case to separate sets from vectors in the core. While this may be useful in programming languages, VAST deals with immutable data where set constraints have been enforced upstream. This change requires updating existing schemas by changing set<T> to vector<T>. In the query language, the new symbol for the empty map changed from {-} to {}, as it now unambiguously identifies map instances. #1010

• The expression field parser now allows the '-' character. #999

🎁 Features

• The default schema for Suricata has been updated to support the suricata.ftp and suricata.ftp_data event types. #1009

• VAST now prints the location of the configuration file that is used. #1009

• VAST now writes a PID lock file on startup to prevent multiple server processes from accessing the same persistent state. The pid.lock file resides in the vast.db directory. #1001

🐞 Bug Fixes

• VAST did not terminate when a critical component failed during startup. VAST now binds the lifetime of the node to all critical components. #1028

• VAST would overwrite existing on-disk state data when encountering a partial read during startup. This state-corrupting behavior no longer exists. #1026

• Incomplete reads have not been handled properly, which manifested for files larger than 2GB. On macOS, writing files larger than 2GB may have failed previously. VAST now respects OS-specific constraints on the maximum block size. #1025

• The shutdown process of the server process could potentially hang forever. VAST now uses a 2-step procedure that first attempts to terminate all components cleanly. If that fails, it will attempt a hard kill afterwards, and if that fails after another timeout, the process will call abort(3). #1005

• When running VAST under heavy load, CAF stream slot ids could wrap around after a few days and deadlock the system. As a workaround, we extended the slot id bit width to make the time until this happens unrealistically large. #1020

• Some file descriptors remained open when they weren't needed any more. This descriptor leak has been fixed. #1018

• Importing JSON no longer fails for JSON fields containing null when the corresponding VAST type in the schema is a non-trivial type like vector<string>. #1009

• The port encoding for Arrow-encoded table slices is now host-independent and always uses network-byte order. #1007

• When continuous query in a client process terminated, the node did not clean up the corresponding server-side state. This memory leak no longer exists. #1006

• A bug in the expression parser prevented the correct parsing of fields starting with either 'F' or 'T'. #999

• MessagePack-encoded table slices now work correctly for nested container types. #984

2020.07.28

⚡️ Breaking Changes

• FlatBuffers is now a required dependency for VAST. The archive and the segment store use FlatBuffers to store and version their on-disk persistent state. #972

⚠️ Changes

• VAST now recognizes /etc/vast/schema as an additional default directory for schema files. #980

• The suricata schema file contains new type definitions for the stats, krb5, smb, and ssh events. #954 #986

🎁 Features

• We open-sourced our MessagePack-based table slice implementation, which provides a compact row-oriented encoding of data. This encoding works well for binary formats (e.g., PCAP) and access patterns that involve materializing entire rows. The MessagePack table slice is the new default when Apache Arrow is unavailable. To enable parsing into MessagePack, you can pass --table-slice-type=msgpack to the import command, or set the configuration option import.table-slice-type to 'msgpack'. #975

• Starting with this release, installing VAST on any Linux becomes significantly easier: A static binary will be provided with each release on the GitHub releases page. #966

🐞 Bug Fixes

• The PCAP reader now correctly shows the amount of generated events. #954

2020.06.25

⚠️ Changes

• The options system.table-slice-type and system.table-slice-size have been removed, as they duplicated import.table-slice-type and import.table-slice-size respectively. #908 #951

• The default table slice type has been renamed to caf. It has not been the default when built with Apache Arrow support for a while now, and the new name more accurately reflects what it is doing. #948

• The JSON export format now renders timestamps using strings instead of numbers in order to avoid possible loss of precision. #909

🧬 Experimental Features

• VAST now supports aging out existing data. This feature currently only concerns data in the archive. The options system.aging-frequency and system.aging-query configure a query that runs on a regular schedule to determine which events to delete. It is also possible to trigger an aging cycle manually. #929

🎁 Features

• The output format for the explore and pivot commands can now be set using the explore.format and pivot.format options respectively. Both default to JSON. #921

• The meta index now uses Bloom filters for equality queries involving IP addresses. This especially accelerates queries where the user wants to know whether a certain IP address exists in the entire database. #931

• The import command gained a new --read-timeout option that forces data to be forwarded to the importer regardless of the internal batching parameters and table slices being unfinished. This allows for reducing the latency between the import command and the node. The default timeout is 10 seconds. #916

• VAST now has options to limit the amount of results produced by an invocation of vast explore. #882

• The import json command's type restrictions are more relaxed now, and can additionally convert from JSON strings to VAST internal data types. #891

• VAST now supports /etc/vast/vast.conf as an additional fallback for the configuration file. The following file locations are looked at in order: Path specified on the command line via --config=path/to/vast.conf, vast.conf in current working directory, ${INSTALL_PREFIX}/etc/vast/vast.conf, and /etc/vast/vast.conf. #898

🐞 Bug Fixes

• A bogus import process that assembled table slices with a greater number of events than expected by the node was able to lead to wrong query results. #908

• A use after free bug would sometimes crash the node while it was shutting down. #896

• The export json command now correctly unescapes its output. #910

• VAST now correctly checks for control characters in inputs. #910

2020.05.28

⚠️ Changes

• Spreading a query over multiple command line arguments in commands like explore/export/pivot/etc. has been deprecated. #878

• The command line flag for disabling the accountant has been renamed to --disable-metrics to more accurately reflect its intended purpose. The internal vast.statistics event has been renamed to vast.metrics. #870

🧬 Experimental Features

• Added a new explore command to VAST that can be used to show data records within a certain time from the results of a query. #873 #877

🎁 Features

• VAST now ships with a schema suitable for Sysmon import. #886

• When importing events of a new or updated type, VAST now only requires the type to be specified once (e.g., in a schema file). For consecutive imports, the event type does not need to be specified again. A list of registered types can now be viewed using vast status under the key node.type-registry.types. #875

• When importing JSON data without knowing the type of the imported events a priori, VAST now supports automatic event type deduction based on the JSON object keys in the data. VAST selects a type iff the set of fields match a known type. The --type / -t option to the import command restricts the matching to the set of types that share the provided prefix. Omitting -t attempts to match JSON against all known types. If only a single variant of a type is matched, the import falls back to the old behavior and fills in nil for mismatched keys. #875

• VAST now prints a message when it is waiting for user input to read a query from a terminal. #878

• All input parsers now support mixed \n and \r\n line endings. #865

🐞 Bug Fixes

• Fixed a bug that caused vast import processes to produce 'default' table slices, despite having the 'arrow' type as the default. #866

• Fixed a bug where setting the logger.file-verbosity in the config file would not have an effect. #866

• The parser for Zeek tsv data used to ignore attributes that were defined for the Zeek-specific types in the schema files. It has been modified to respect and prefer the specified attributes for the fields that are present in the input data. #847

2020.04.29

⚠️ Changes

• The option --skip-candidate-checks / -s for the count command was renamed to --estimate / -e. #843

• The index specific options max-partition-size, max-resident-partitions, max-taste-partitions, and max-queries can now be specified on the command line when starting a node. #728

• The default bind address has been changed from :: to localhost. #828

🎁 Features

• Bash autocompletion for vast is now available via the autocomplete script located at scripts/vast-completions.bash in the VAST source tree. #833

• Packet drop and discard statistics are now reported to the accountant for PCAP import, and are available using the keys pcap-reader.recv, pcap-reader.drop, pcap-reader.ifdrop, pcap-reader.discard, and pcap-reader.discard-rate in the vast.statistics event. If the number of dropped packets exceeds a configurable threshold, VAST additionally warns about packet drops on the command line. #827 #844

🐞 Bug Fixes

• The stop command always returned immediately, regardless of whether it succeeded. It now blocks until the remote node shut down properly or returns an error exit code upon failure. #849

• For some queries, the index evaluated only a subset of all relevant partitions in a non-deterministic manner. Fixing a violated evaluation invariant now guarantees deterministic execution. #842

• Fixed a crash when importing data while a continuous export was running for unrelated events. #830

• Fixed a bug that could cause stalled input streams not to forward events to the index and archive components for the JSON, CSV, and Syslog readers, when the input stopped arriving but no EOF was sent. This is a follow-up to #750. A timeout now ensures that that the readers continue when some events were already handled, but the input appears to be stalled. #835

• Queries of the form x != 80/tcp were falsely evaluated as x != 80/? && x != ?/tcp. (The syntax in the second predicate does not yet exist; it only illustrates the bug.) Port inequality queries now correctly evaluate x != 80/? || x != ?/tcp. E.g., the result now contains values like 80/udp and 80/?, but also 8080/tcp. #834

• Archive lookups are now interruptible. This change fixes an issue that caused consecutive exports to slow down the node, which improves the overall performance for larger databases considerably. #825

2020.03.26

⚠️ Changes

• The config option system.log-directory was deprecated and replaced by the new option system.log-file. All logs will now be written to a single file. #806

• The log folder vast.log/ in the current directory will not be created by default any more. Users must explicitly set the system.file-verbosity option if they wish to keep the old behavior. #803

• The VERBOSE log level has been added between INFO and DEBUG. This level is enabled at build time for all build types, making it possible to get more detailed logging output from release builds. #787

• The command line options prefix for changing CAF options was changed from --caf# to --caf.. #797

• The internal statistics event type vast.account has been renamed to vast.statistics for clarity. #789

🎁 Features

• The new vast import syslog command allows importing Syslog messages as defined in RFC5424. #770

• The hash index has been re-enabled after it was outfitted with a new high-performance hash map implementation that increased performance to the point where it is on par with the regular index. #796

• The option --disable-community-id has been added to the vast import pcap command for disabling the automatic computation of Community IDs. #777

🐞 Bug Fixes

• An under-the-hood change to our parser-combinator framework makes sure that we do not discard possibly invalid input data up the the end of input. This uncovered a bug in our MRT/bgpdump integrations, which have thus been disabled (for now), and will be fixed at a later point in time. #808

• Expressions must now be parsed to the end of input. This fixes a bug that caused malformed queries to be evaluated until the parser failed. For example, the query #type == "suricata.http" && .dest_port == 80 was erroneously evaluated as #type == "suricata.http" instead. #791

• The short option -c for setting the configuration file has been removed. The long option --config must now be used instead. This fixed a bug that did not allow for -c to be used for continuous exports. #781

• Continuous export processes can now be stopped correctly. Before this change, the node showed an error message and the exporting process exited with a non-zero exit code. #779

2020.02.27

⚠️ Changes

• Hash indices have been disabled again due to a performance regression. #765

• The option --directory has been replaced by --db-directory and log-directory, which set directories for persistent state and log files respectively. The default log file path has changed from vast.db/log to vast.log. #758

• VAST now supports (and requires) Apache Arrow >= 0.16. #751

• The option --historical for export commands has been removed, as it was the default already. #754

• The build system will from now on try use the CAF library from the system, if one is provided. If it is not found, the CAF submodule will be used as a fallback. #740

🎁 Features

• For users of the Nix package manager, expressions have been added to generate reproducible development environments with nix-shell. #740

🐞 Bug Fixes

• Continuously importing events from a Zeek process with a low rate of emitted events resulted in a long delay until the data would be included in the result set of queries. This is because the import process would buffer up to 10,000 events before sending them to the server as a batch. The algorithm has been tuned to flush its buffers if no data is available for more than 500 milliseconds. #750

2020.01.31

⚠️ Changes

• VAST is switching to a calendar-based versioning scheme starting with this release. #739

• Record field names can now be entered as quoted strings in the schema and expression languages. This lifts a restriction where JSON fields with whitespaces or special characters could not be ingested. #685

• Two minor modifications were done in the parsing framework: (i) the parsers for enums and records now allow trailing separators, and (ii) the dash (-) was removed from the allowed characters of schema type names. #706

• Build configuration defaults have been adapated for a better user experience. Installations are now relocatable by default, which can be reverted by configuring with --without-relocatable. Additionally, new sets of defaults named --release and --debug (renamed from --dev-mode) have been added. #695

• The import pcap command no longer takes interface names via --read,-r, but instead from a separate option named --interface,-i. This change has been made for consistency with other tools. #641

🎁 Features

• When a record field has the #index=hash attribute, VAST will choose an optimized index implementation. This new index type only supports (in)equality queries and is therefore intended to be used with opaque types, such as unique identifiers or random strings. #632, #726

• An experimental new Python module enables querying VAST and processing results as pyarrow tables. #685

• On FreeBSD, a VAST installation now includes an rc.d script that simpliefies spinning up a VAST node. CMake installs the script at PREFIX/etc/rc.d/vast. #693

• The long option --config, which sets an explicit path to the VAST configuration file, now also has the short option -c. #689

• Added Apache Arrow as new export format. This allows users to export query results as Apache Arrow record batches for processing the results downstream, e.g., in Python or Spark. #633

• The import pcap command now takes an optional snapshot length via --snaplen. If the snapshot length is set to snaplen, and snaplen is less than the size of a packet that is captured, only the first snaplen bytes of that packet will be captured and provided as packet data. #642

🐞 Bug Fixes

• A bug in the quoted string parser caused a parsing failure if an escape character occurred in the last position. #685

• The example configuration file contained an invalid section vast. This has been changed to the correct name system. #705

• A race condition in the index logic was able to lead to incomplete or empty result sets for vast export. #703

• The import process did not print statistics when importing events over UDP. Additionally, warnings about dropped UDP packets are no longer shown per packet, but rather periodically reported in a readable format. #662

• Importing events over UDP with vast import <format> --listen :<port>/udp failed to register the accountant component. This caused an unexpected message warning to be printed on startup and resulted in losing import statistics. VAST now correctly registers the accountant. #655

• PCAP ingestion failed for traces containing VLAN tags. VAST now strips IEEE 802.1Q headers instead of skipping VLAN-tagged packets. #650

• In some cases it was possible that a source would connect to a node before it was fully initialized, resulting in a hanging vast import process. #647

0.2 - 2019.10.30

⚠️ Changes

• The query language has been extended to support expression of the form X == /pattern/, where X is a compatible LHS extractor. Previously, patterns only supports the match operator ~. The two operators have the same semantics when one operand is a pattern.

• CAF and Broker are no longer required to be installed prior to building VAST. These dependencies are now tracked as git submodules to ensure version compatibility. Specifying a custom build is still possible via the CMake variables CAF_ROOT_DIR and BROKER_ROOT_DIR.

• When exporting data in pcap format, it is no longer necessary to manually restrict the query by adding the predicate #type == "pcap.packet" to the expression. This now happens automatically because only this type contains the raw packet data.

• When defining schema attributes in key-value pair form, the value no longer requires double-quotes. For example, #foo=x is now the same as #foo="x". The form without double-quotes consumes the input until the next space and does not support escaping. In case an attribute value contains whitespace, double-quotes must be provided, e.g., #foo="x y z".

• The PCAP packet type gained the additional field community_id that contains the Community ID flow hash. This identifier facilitates pivoting to a specific flow from data sources with connnection-level information, such Zeek or Suricata logs.

• Log files generally have some notion of timestamp for recorded events. To make the query language more intuitive, the syntax for querying time points thus changed from #time to #timestamp. For example, #time > 2019-07-02+12:00:00 now reads #timestamp > 2019-07-02+12:00:00.

• Default schema definitions for certain import formats changed from hard-coded to runtime-evaluated. The default location of the schema definition files is $(dirname vast-executable)/../share/vast/schema. Currently this is used for the Suricata JSON log reader.

• The default directory name for persistent state changed from vast to vast.db. This makes it possible to run ./vast in the current directory without having to specify a different state directory on the command line.

• Nested types are from now on accessed by the .-syntax. This means VAST now has a unified syntax to select nested types and fields. For example, what used to be zeek::http is now just zeek.http.

• The (internal) option --node for the import and export commands has been renamed from -n to -N, to allow usage of -n for --max-events.

• To make the export option to limit the number of events to be exported more idiomatic, it has been renamed from --events,e to --max-events,n. Now vast export -n 42 generates at most 42 events.

🎁 Features

• The default schema for Suricata has been updated to support the new suricata.smtp event type in Suricata 5.

• The export null command retrieves data, but never prints anything. Its main purpose is to make benchmarking VAST easier and faster.

• The new pivot command retrieves data of a related type. It inspects each event in a query result to find an event of the requested type. If a common field exists in the schema definition of the requested type, VAST will dynamically create a new query to fetch the contextual data according to the type relationship. For example, if two records T and U share the same field x, and the user requests to pivot via T.x == 42, then VAST will fetch all data for U.x == 42. An example use case would be to pivot from a Zeek or Suricata log entry to the corresponding PCAP packets. VAST uses the field community_id to pivot between the logs and the packets. Pivoting is currently implemented for Suricata, Zeek (with community ID computation enabled), and PCAP.

• The new infer command performs schema inference of input data. The command can deduce the input format and creates a schema definition that is sutable to use with the supplied data. Supported input types include Zeek TSV and JSONLD.

• The newly added count comman allows counting hits for a query without exporting data.

• Commands now support a --documentation option, which returns Markdown-formatted documentation text.

• A new schema for Argus CSV output has been added. It parses the output of ra(1), which produces CSV output when invoked with -L 0 -c ,.

• The schema language now supports comments. A double-slash (//) begins a comment. Comments last until the end of the line, i.e., until a newline character (\n).

• The import command now supports CSV formatted data. The type for each column is automatically derived by matching the column names from the CSV header in the input with the available types from the schema definitions.

• Configuring how much status information gets printed to STDERR previously required obscure config settings. From now on, users can simply use --verbosity=<level>,-v <level>, where <level> is one of quiet, error, warn, info, debug, or trace. However, debug and trace are only available for debug builds (otherwise they fall back to log level info).

• The query expression language now supports data predicates, which are a shorthand for a type extractor in combination with an equality operator. For example, the data predicate 6.6.6.6 is the same as :addr == 6.6.6.6.

• The index object in the output from vast status has a new field statistics for a high-level summary of the indexed data. Currently, there exists a nested layouts objects with per-layout statistics about the number of events indexed.

• The accountant object in the output from vast status has a new field log-file that points to the filesystem path of the accountant log file.

• Data extractors in the query language can now contain a type prefix. This enables an easier way to extract data from a specific type. For example, a query to look for Zeek conn log entries with responder IP address 1.2.3.4 had to be written with two terms, #type == zeek.conn && id.resp_h == 1.2.3.4, because the nested id record can occur in other types as well. Such queries can now written more tersely as zeek.conn.id.resp_h == 1.2.3.4.

• VAST gained support for importing Suricata JSON logs. The import command has a new suricata format that can ingest EVE JSON output.

• The data parser now supports count and integer values according to the International System for Units (SI). For example, 1k is equal to 1000 and 1Ki equal to 1024.

• VAST can now ingest JSON data. The import command gained the json format, which allows for parsing line-delimited JSON (LDJSON) according to a user-selected type with --type. The --schema or --schema-file options can be used in conjunction to supply custom types. The JSON objects in the input must match the selected type, that is, the keys of the JSON object must be equal to the record field names and the object values must be convertible to the record field types.

• For symmetry to the export command, the import command gained the --max-events,n option to limit the number of events that will be imported.

• The import command gained the --listen,l option to receive input from the network. Currently only UDP is supported. Previously, one had to use a clever netcat pipe with enough receive buffer to achieve the same effect, e.g., nc -I 1500 -p 4200 | vast import pcap. Now this pipe degenerates to vast import pcap -l.

• The new --disable-accounting option shuts off periodic gathering of system telemetry in the accountant actor. This also disables output in the accounting.log.

🐞 Bug Fixes

• The user environments LDFLAGS were erroneously passed to ar. Instead, the user environments ARFLAGS are now used.

• Exporting data with export -n <count> crashed when count was a multiple of the table slice size. The command now works as expected.

• Queries of the form #type ~ /pattern/ used to be rejected erroneously. The validation code has been corrected and such queries are now working as expected.

• When specifying enum types in the schema, ingestion failed because there did not exist an implementation for such types. It is now possible to use define enumerations in schema as expected and query them as strings.

• Queries with the less < or greater > operators produced off-by-one results for the duration when the query contained a finer resolution than the index. The operator now works as expected.

• Timestamps were always printed in millisecond resolution, which lead to loss of precision when the internal representation had a higher resolution. Timestamps are now rendered up to nanosecond resolution - the maximum resolution supported.

• All query expressions in the form #type != X were falsely evaluated as #type == X and consequently produced wrong results. These expressions now behave as expected.

• Parsers for reading log input that relied on recursive rules leaked memory by creating cycling references. All recursive parsers have been updated to break such cycles and thus no longer leak memory.

• The Zeek reader failed upon encountering logs with a double column, as it occurs in capture_loss.log. The Zeek parser generator has been fixed to handle such types correctly.

• Some queries returned duplicate events because the archive did not filter the result set properly. This no longer occurs after fixing the table slice filtering logic.

• The map data parser did not parse negative values correctly. It was not possible to parse strings of the form "{-42 -> T}" because the parser attempted to parse the token for the empty map "{-}" instead.

• The CSV printer of the export command used to insert 2 superfluous fields when formatting an event: The internal event ID and a deprecated internal timestamp value. Both fields have been removed from the output, bringing it into line with the other output formats.

• When a node terminates during an import, the client process remained unaffected and kept processing input. Now the client terminates when a remote node terminates.

• Evaluation of predicates with negations return incorrect results. For example, the expression :addr !in 10.0.0.0/8 created a disjunction of all fields to which :addr resolved, without properly applying De-Morgan. The same bug also existed for key extractors. De-Morgan is now applied properly for the operations !in and !~.

0.1 - 2019.02.28

This is the first official release.