The TDS configuration file ${tomcat_home}/content/thredds/threddsConfig.xml allows the TDS
administrator to control the behavior of the TDS.
This is the complete reference document for TDS version 4.6.
In general, you do not have to change any of these parameters, since the TDS will
use default settings. If you do change any of these, you must restart the thredds
webapp (e.g., through the tomcat manager application) for them to take effect. The
exception is that the catalogRoot elements will be reread by
doing a Debug/Reinit, if you have remote management enabled.
Here
is an annotated example threddsConfig.xml.
Contents
In the serverInformation element, you can provide basic
information about your server including contact information, and
information about the group that hosts the server.
<serverInformation>
<name>Initial TDS Installation</name>
<logoUrl>/thredds/threddsIcon.gif</logoUrl>
<logoAltText>Initial TDS Installation</logoAltText>
<abstract>Scientific Data</abstract>
<keywords>meteorology, atmosphere, climate, ocean, earth science</keywords>
<contact>
<name>Support</name>
<organization>My Group</organization>
<email>support@my.group</email>
<phone></phone>
</contact>
<hostInstitution>
<name>My Group</name>
<webSite>http://www.my.group/</webSite>
<logoUrl>myGroup.gif</logoUrl>
<logoAltText>My Group</logoAltText>
</hostInstitution>
</serverInformation>
The information provided in the serverInformation element is used in:
NOTE: The best way to use your own logo is to put it in the ${tomcat_home}/content/thredds/public/
directory, and specify it in serverInformation as /thredds/<name>, e.g.:
<logoUrl>/thredds/yourIcon.gif</logoUrl>
The TDS supports the following requests for server information:
/thredds/serverInfo.html (sample response)
/thredds/serverInfo.xml (sample response)/thredds/serverVersion.txt (sample response)In the htmlSetup element, you can configure which CSS
documents are used in all the HTML pages generated by the TDS. Default CSS files are provided with the thredds.war distribution, and should not be modified.
Instead, these can be overridden by placing the appropriate CSS files in the ${tomcat_home}/content/thredds/public/ directory and pointing to
them here:
<htmlSetup> 1) <standardCssUrl>tds.css</standardCssUrl> 2) <catalogCssUrl>tdsCat.css</catalogCssUrl> 3) <openDapCssUrl>tdsDap.css</openDapCssUrl> 4) <googleTrackingCode>UA-54516992-1</googleTrackingCode> </htmlSetup>where:
since version 4.1
<catalogWriting> <useBytesForDataSize>false<useBytesForDataSize/> </catalogWriting>
<catalogRoot>tempCatalog.xml</catalogRoot> <catalogRoot>idd/catalog.xml</catalogRoot> <catalogRoot>catgen/subdir/enhancedCatalog-1.0.xml</catalogRoot>
These elements name your root catalogs that are not referenced from your main catalog ( ${tomcat_home}/content/thredds/catalog.xml). On startup, the TDS reads the main catalog and any root catalogs you list here, plus any catalogs that are referenced by them in a catalogRef. Data roots and other needed information are found and cached. All the catalogs found in this way are called static catalogs, and all static catalogs must live under the ${tomcat_home}/content/thredds directory.
<Viewer>my.package.MyViewer</Viewer>
You can place a link to your own Viewer on the TDS HTML page, by loading a viewer at runtime. This line is needed in the config file only if you are writing your own Java class.
<datasetSource>my.package.DatasetSourceImpl</datasetSource>
You can add a DataSource - essentially an IOSP with access to Servlet request parameters, by loading a dataset source at runtime.
<TdsUpdateConfig> <logVersionInfo>true</logVersionInfo> </TdsUpdateConfig>
The TdsUpdateConfig element controls if the TDS checks with Unidata regarding possible updates. The default (true) is for the TDS to check for the current stable and development release versions, and to log that information in the TDS serverStartup.log file as INFO entries. If you do not want the TDS to check for this on startup, set this to false.
Catalog services are available by default for catalogs served by the local TDS. But for remote catalogs these services must be explicitly enabled in threddsConfig.xml:
<CatalogServices> <allowRemote>true</allowRemote> </CatalogServices>
<Opendap> <ascLimit>50</ascLimit> <binLimit>500</binLimit> <serverVersion>opendap/3.7</serverVersion> </Opendap>
This controls the OPeNDAP data service. Because its easy for a user to inadvertantly request very large amounts of data, the TDS limits the size of the data response. In our experience legitimate requests ask for subset sizes that are well below the defaults.
The OGC WCS service provided as part of the TDS is described in more detail here.
By default this service is disabled. It can be enabled by including the following in the
threddsConfig.xml file:
<WCS> <allow>true</allow> </WCS>
The following shows all the configuration options available in the WCS section of the threddsConfig.xml file with the default values shown:
<WCS> <allow>false</allow> <dir>(see the note below)</dir> <scour>15 min</scour> <maxAge>30 min</maxAge> </WCS>
We recommend that you include in the threddsConfig.xml file only the options you want to change. Here is the description of the
various options:
The OGC WMS service provided as part of the TDS is described in more detail here.
By default this service is disabled. It can be enabled by including the following in the threddsConfig.xml file:
<WMS> <allow>true</allow> </WMS>
The following shows all the configuration options available in the WMS section of the
threddsConfig.xml file with the default values shown:
<WMS> <allow>false</allow> <allowRemote>false</allowRemote> <paletteLocationDir>/WEB-INF/palettes</paletteLocationDir> <maxImageWidth>2048</maxImageWidth> <maxImageHeight>2048</maxImageHeight> </WMS>
We recommend that you include in the threddsConfig.xml file only the options you
want to change. Here is the description of the various options:
The NetCDF Subset Service provided as part of the TDS is described in more detail here. By default this service is disabled. It can be enabled by including the following in the
threddsConfig.xml file:
<NetcdfSubsetService> <allow>true</allow> </NetcdfSubsetService>
The following shows all the configuration options available in the NetcdfSubsetService section of the threddsConfig.xml file with the default values shown:
<NetcdfSubsetService> <allow>false</allow> <dir>(see the note below)</dir> <scour>15 min</scour> <maxAge>30 min</maxAge> <maxFileDownloadSize>300 MB</maxFileDownloadSize> </NetcdfSubsetService>
We recommend that you include in the threddsConfig.xml file only the options you want to change. Here is the description of the
various options:
By default the ncISO services are disabled in the TDS. They can be enabled by including the following in the threddsConfig.xml file:
<NCISO> <ncmlAllow>true</ncmlAllow> <uddcAllow>true</uddcAllow> <isoAllow>true</isoAllow> </NCISO>
Each of the allow elements above enables the corresponding ncISO service (NCML, UDDC, and ISO). The ncISO services are described in more detail on the ncISO page.
By default the ncSOS service is disabled in the TDS. It can be enabled by including the following in the threddsConfig.xml file:
<NCSOS> <allow>true</allow> </NCSOS>
The allow element enables the SOS service. For more information, see the OGC SOS page, or the ncSOS wiki, maintained by the developers of the ncSOS plugin, Applied Science Associates.
<FeatureCollection>
<RollingFileAppender>
<MaxFileSize>1 MB</MaxFileSize>
<MaxBackups>10</MaxBackups>
<Level>INFO</Level>
</RollingFileAppender>
</FeatureCollection>
Feature Collection logs are placed in ${tomcat_home}/content/thredds/logs/fc.<collectionName>.log. These are programatically added and therefore cannot be configured in log4j2.xml. By default, each Feature Collection will rollover at 1 MB, and 5 files will be kept. Messages at the level of INFO and above will be enabled. You can change those settings here (note that your changes will apply to all Feature Collections).
<Netcdf4Clibrary> <libraryPath>/usr/local/lib</libraryPath> <libraryName>netcdf</libraryName> <useForReading>false</useForReading> </Netcdf4Clibrary>
In order to write netCDF-4 files, you must have the netCDF-4 C library—version 4.3.1 or above—compiled and available on your system, along with all supporting libraries (HDF5, zlib, and curl). The details of this differ for each operating system. The elements above allow you to configure how the library is discovered and used.
true, then
it will be used for reading NetCDF-4 (and HDF5) files as well.For TDS users, we recommend setting the library path and name in threddsConfig.xml as in the above example.
<nj22Config> <ioServiceProvider class="edu.univ.ny.stuff.FooFiles"/> <coordSysBuilder convention="foo" class="test.Foo"/> <coordTransBuilder name="atmos_ln_sigma_coordinates" type="vertical" class="my.stuff.atmosSigmaLog"/> <typedDatasetFactory datatype="Point" class="gov.noaa.obscure.file.Flabulate"/> <table type="GRIB1" filename="/home/rkambic/grib/tables/userlookup.lst"/> <table type="GRIB2" filename="/home/rkambic/grib/tables/grib2userparameters"/> </nj22Config>
These elements allow you to specify runtime parameters for the Netcdf-Java library from the threddsConfig file. See the Netcdf-Java tutorial for an overview.
<Aggregation> <typicalDataset>penultimate</typicalDataset> </Aggregation>
You can control how NcML Aggregation chooses its typical/template dataset — the one it uses to populate the metadata for the resulting aggregated dataset. Valid values are first, random, latest, and penultimate (latest but one). The default is penultimate.
The various cache directory locations are all under {tomcat_home}/content/thredds/ by default:
cache location description AggregationCache.dir cache/agg/ for joinExisting aggregations only: write XML files here. CdmRemote.dir cache/cdmr/ temporary files for cdmremote and cdmrFeature CdmValidatorService.dir cache/cdmValidate/ temporary files for cdmvalidator (seperate war) DiskCache.dir cache/cdm/ only used when non-writeable data directory or alwaysUse = true; puts CDM indexes, decompressed files, etc. into this directory
ehcache.dir cache/ehcache/ object cache, put ehcache backup file in this directory FeatureCollectionCache.dir cache/collection/ when we read GridDataset for FMRC, write an XML summary, store in BDB in this directory NetcdfSubsetService.dir cache/ncss/ temporary files for NCSS WCS.dir cache/wcs/ temporary files for WCS
We recommend that you use these defaults, by not specifying them in the threddsConfig.xml file. If you need to move the cache location, move all of them by using a symbolic file link in {tomcat_home}/content/thredds/. At Unidata, we move the entire content directory by creating a symbolic link:
cd {tomcat_home}
ln -s /data/thredds/content content
These various caches at times may contain large amounts of data. You should choose a location that will not fill up (especially if that location affects other important locations like /opt, /home, etc). If you have a large disk for your data, that may be a good location for the cache directories. On unix-like machines, you can run 'df' to get a listing of disks on your machine. The listing includes size and mount location.
The following elements allow fine grain control over the location and scouring of each of these.
<DiskCache> <alwaysUse>false</alwaysUse> <dir>/temp/cache/</dir> <scour>1 hour</scour> <maxSize>10 Gb</maxSize> </DiskCache>
These elements control where the CDM/NetCDF-Java library writes temporary files, for example when it needs to unzip files, or write GRIB index files, etc. If alwaysUse is true, these temporary files will always be written to the cache directory specified by dir (choosing a cache directory). If alwaysUse is false, TDS will try to write them to the same directory as the original file, and if the TDS doesnt have write permission it will then write the files to the cache directory. Write permission will be determined by what rights the Tomcat user has (the user that starts up Tomcat). For security reasons, you want to carefully limit the file permissions of the Tomcat user.
When opening a file, if alwaysUse is true, TDS looks only in the cache directory for the temporary file. If alwaysUse is false, TDS will first look for the temporary file in the same directory as the original file, and if not found, then will look in the cache.
Every scour amount of time, the largest items in the cache will be deleted, until the directory has less than maxSize bytes. Note that the directory will sometimes exceed maxSize, and will only be knocked back to maxSize when the scour thread runs. To turn off scouring, set the scour time to 0 (eg "0 secs").
If not otherwise set, the TDS will use the ${tomcat_home}/content/thredds/cache/cdm directory. We recommend that you use this default, by not specifying the DiskCache.dir element.
since version 4.1
<AggregationCache> <dir>/tomcat_home/content/thredds/cache/agg/</dir> <scour>24 hours</scour> <maxAge>90 days</maxAge> <cachePathPolicy>nestedDirectory</cachePathPolicy> </AggregationCache>
If you have joinExisting Aggregations, coordinate information will be written to a cache directory specified by dir (choosing a cache directory). If not otherwise set, the TDS will use the ${tomcat_home}/content/thredds/cache/agg/ directory. We recommend that you use this default, by not specifying a AggregationCache.dir element.
Every scour amount of time, any item that hasnt been changed since maxAge time will be deleted. If you have aggregations that never change, set scour to "-1" to disable the operation. Otherwise, make maxAge longer than the longest time between changes. Basically, you don't want to remove active aggregations.
cachePathPolicy controls how cache files are stored in dir. It must be
set to one of oneDirectory or nestedDirectory (the default).
oneDirectory will put all cache files into the same directory, while
nestedDirectory will preserve their directory structure. Use nestedDirectory
for large aggregations, as some file systems struggle when a directory contains thousands of files.
This cache information is intended to be permanent; it stores coordinate information from each file in the aggregation, so that the file does not have to be opened each time the dataset is opened. If you have large joinExisting aggregations, there will be a very pronounced difference with and without this cache.
The cache information is updated based on the recheckEvery field in the joinExisting aggregation element.
since version 4.2
This is where persistent information is kept about FMRCs, in order to speed them up. We recommend that you use the default settings, by not specifying this option.
<FeatureCollection>
<dir>/tomcat_home/content/thredds/cache/collection/</dir> <maxSize>20 Mb</maxSize> <jvmPercent>2</jvmPercent>
</FeatureCollection>
since version 4.3.15
<GribIndex> <alwaysUse>false</alwaysUse> <neverUse>false</neverUse> <dir>/tomcat_home/content/thredds/cache/grib/</dir> <policy>nestedDirectory</policy> <scour>0 hours</scour> <maxAge>90 days</maxAge> </GribIndex>
These elements control where Grib index files are written.
If alwaysUse is true, grib index files will always be written to the index directory specified by dir (choosing a cache directory). If neverUse is true, the index directory will never be used. If neither is set, the TDS will try to write grib indexes to the same directory as the original file, and if the TDS doesnt have write permission it will then write the files to the index directory. Write permission will be determined by what rights the Tomcat user has (the user that starts up Tomcat). For security reasons, you want to carefully limit the file permissions of the Tomcat user.
The policy must be set to one of oneDirectory or nestedDirectory (the default). oneDirectory will put all index files into the same directory, while nestedDirectory will preserve the directory structure of the index files. Use nestedDirectory for large collections of files, as some file systems struggle when a directory contains thousands of files.
Managing the GRIB indices is an important task, and can be difficult if the files are changing, as in a rolling archive, or for very large collections. There are two typical ways to do this:
A good rule of thumb is that the index files will need disk space between 500 and 1000 times smaller than the size of the grib data files. So a 1 Terabyte collection of GRIB data will need up to 2 GB of indices.
The default settings will work well enough, and you should only tune them if you have performance problems, and are able to monitor their effect.
<RandomAccessFile> <minFiles>400</minFiles> <maxFiles>500</maxFiles> <scour>11 min</scour> </RandomAccessFile>
There is a pool of shared RandomAccessFile objects, each of which stores an open OS file handle. Since each OS has a maximum on the number of open file handles per process, you must make sure that the sum of the maxFiles does not exceed your OS maximum. For better performance, make these numbers as high as possible.
<NetcdfFileCache> <minFiles>100</minFiles> <maxFiles>150</maxFiles> <scour>12 min</scour> </NetcdfFileCache>
<TimePartition> <minFiles>100</minFiles> <maxFiles>150</maxFiles> <scour>13 min</scour> </TimePartition>
These elements control the size of the TDS cache for objects for 1) NetcdfFile objects, and 2) Grib Partition files, respectively. Up to maxFiles objects will be cached, and every scour amount of time, older items in the cache will be released, until only minFiles objects are left. The scour element uses any valid udunits time string, such as sec, min, hour, day. To disable the cache, set maxFiles to 0.
since version 4.2.8
Static catalogs are cached for performance, under the assumption there are a small number of them. If you have a large number of static catalogs, you may turn caching off to save memory, at the cost of some performace slowdown. Root catalogs are always cached, as are catalogs with datasetFmrc and featureCollections in them.
<Catalog> <cache>false</cache> </Catalog>
LOOK the following may not be working
You may also set cache=false on a datasetRoot element. This controls whether a file is put in the NetcdfFile object cache. All files that are found through that datasetRoot are affected. Example:
<catalog xmlns="http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0"
xmlns:xlink="http://www.w3.org/1999/xlink" name="THREDDS Catalog for NetCDF Files" version="1.0.3">
<service name="ncdods" serviceType="OpenDAP" base="/thredds/dodsC/"/>
<datasetRoot path="FVCOM" location="/http/www/CODFISH/Data/COM/" cache="false"/>
<datasetRoot path="ZZTOP" location="/http/www/CODFISH/Data/ZCOM/" />
<dataset name="GOM2 Forecast" ID="gom2_nocache" serviceName="ncdods" urlPath="FVCOM/NECOFS/Forecasts/NECOFS_GOM2_FORECAST.nc" dataType="Grid"/>
<dataset name="GOM3 Forecast" ID="gom3_nocache" serviceName="ncdods" urlPath="FVCOM/NECOFS/Forecasts/NECOFS_GOM3_FORECAST.nc" dataType="Grid"/>
<dataset name="MASSBAY Forecast" ID="massbay_nocache" serviceName="ncdods" urlPath="ZZTOP/NECOFS/Forecasts/NECOFS_FVCOM_OCEAN_MASSBAY_FORECAST.nc" dataType="Grid"/>
</catalog>
In the above example, the files
will not be cached, but this one will be cached:
NOT CURRENTLY USED
The ehcache object cache is backed up in this directory. Currently, only OS directory scans are cached here.
<ehcache> <configFile>/tomcat_home/webapp/WEB-INF/ehcache.xml</configFile> <dir>/tomcat_home/content/thredds/ehcache/</dir> </ehcache>
contentRoot ElementDO NOT USE
Intended to chain together multiple "content" directories. For instance, the following:
<contentRoots> <contentRoot>motherlode</contentRoot> <contentRoot>idd</contentRoot> </contentRoots>
chains together:
dataRoot ElementNOT YET IMPLEMENTED
Eventually will provide macro-replacment in datasetScan location attributes. For instance:
<DataRoots> <idd>/data/ldm/pub</idd> </DataRoots>
Could be used with:
<datasetScan ... location="${iddDataRoot}/fsl">...</datasetScan>
This document is maintained by elves and was last updated June 2016.
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