On Fri, 17 Jan 2020 at 13:35, Ryan Skraba <r...@skraba.com> wrote: > Hello! I just created a JIRA for this as an improvement :D > https://issues.apache.org/jira/browse/AVRO-2689 > > To check evolution, we'd probably want to specify the reader schema in > the GenericDatumReader created here: > > https://github.com/apache/avro/blob/master/lang/java/tools/src/main/java/org/apache/avro/tool/DataFileReadTool.java#L75 > > The writer schema is automatically set when the DataFileStream is > created. If we want to set a different reader schema (than the one > found in the file), it should be set by calling > reader.setExpected(readerSchema) just after the DataFileStream is > created. >
Ah, that's a good pointer, thanks! I was looking for an appropriate constructor, but there didn't seem to be one. > > I think it's a pretty good idea -- it feels like we're seeing more > questions about schema evolution these days, so that would be a neat > way for a user to test (or to create reproducible scenarios for bug > reports). If you're interested, feel free to take the JIRA! I'd be > happy to help out. > So, I've had a go at it... see https://github.com/rogpeppe-contrib/avro/commit/1236e9d33207a11d557c1eb2a171972e085dfcf2 I did the following to see if it was working ("avro" is my shell script wrapper around the avro-tools jar): % cat schema.avsc { "name": "R", "type": "record", "fields": [ { "name": "A", "type": { "type": "array", "items": "int" } } ] } % cat schema1.avsc { "name": "R", "type": "record", "fields": [ { "name": "B", "type": "string", "default": "hello" } ] } % AVRO_TOOLS_JAR=/home/rog/other/avro/lang/java/tools/target/avro-tools-1.10.0-SNAPSHOT.ja% avro random --count 1 --schema-file schema.avsc x.out % avro tojson x.out {"A":[-890831012,1123049230,302974832]} % cp schema.avsc schema1.avsc % avro tojson --reader-schema-file schema1.avsc x.out Exception in thread "main" java.lang.ClassCastException: class org.apache.avro.util.Utf8 cannot be cast to class java.util.Collection (org.apache.avro.util.Utf8 is in unnamed module of loader 'app'; java.util.Collection is in module java.base of loader 'bootstrap') at org.apache.avro.generic.GenericDatumWriter.getArraySize(GenericDatumWriter.java:258) at org.apache.avro.generic.GenericDatumWriter.writeArray(GenericDatumWriter.java:228) at org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:136) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:82) at org.apache.avro.generic.GenericDatumWriter.writeField(GenericDatumWriter.java:206) at org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:195) at org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:130) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:82) at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:72) at org.apache.avro.tool.DataFileReadTool.run(DataFileReadTool.java:99) at org.apache.avro.tool.Main.run(Main.java:66) at org.apache.avro.tool.Main.main(Main.java:55) % I am a bit clueless when it comes to interpreting that exception... sorry for the ignorance - this is the first Java code I've ever written! Any idea what's going on? This is maybe getting a bit too noisy for the list - feel to reply directly. cheers, rog. > Ryan > > > On Fri, Jan 17, 2020 at 2:22 PM roger peppe <rogpe...@gmail.com> wrote: > > > > On Thu, 16 Jan 2020 at 17:21, Ryan Skraba <r...@skraba.com> wrote: > >> > >> didn't find anything currently in the avro-tools that uses both > >> reader and writer schemas while deserializing data... It should be a > >> pretty easy feature to add as an option to the DataFileReadTool > >> (a.k.a. tojson)! > > > > > > Thanks for that suggestion. I've been delving into that code a bit and > trying to understand what's going on. > > > > At the heart of it is this code: > > > > GenericDatumReader<Object> reader = new GenericDatumReader<>(); > > try (DataFileStream<Object> streamReader = new > DataFileStream<>(inStream, reader)) { > > Schema schema = streamReader.getSchema(); > > DatumWriter<Object> writer = new GenericDatumWriter<>(schema); > > JsonEncoder encoder = EncoderFactory.get().jsonEncoder(schema, > out, pretty); > > > > I'm trying to work out where the best place to put the specific reader > schema (taken from a command line flag) might be. > > > > Would it be best to do it when creating the DatumReader (it looks like > there might be a way to create that with a generic writer schema and a > specific reader schema, although I can't quite see how to do that atm), or > when creating the DatumWriter? > > Or perhaps there's a better way? > > > > Thanks for any guidance. > > > > cheers, > > rog. > >> > >> > >> You are correct about running ./build.sh dist in the java directory -- > >> it fails with JDK 11 (likely fixable: > >> https://issues.apache.org/jira/browse/MJAVADOC-562). > >> > >> You should probably do a simple mvn clean install instead and find the > >> jar in lang/java/tools/target/avro-tools-1.10.0-SNAPSHOT.jar. That > >> should work with JDK11 without any problem (well-tested in the build). > >> > >> Best regards, Ryan > >> > >> > >> > >> On Thu, Jan 16, 2020 at 5:49 PM roger peppe <rogpe...@gmail.com> wrote: > >> > > >> > Update: I tried running `build.sh dist` in `lang/java` and it failed > (at least, it looks like a failure message) after downloading a load of > Maven deps with the following errors: > https://gist.github.com/rogpeppe/df05d993254dc5082253a5ef5027e965 > >> > > >> > Any hints on what I should do to build the avro-tools jar? > >> > > >> > cheers, > >> > rog. > >> > > >> > On Thu, 16 Jan 2020 at 16:45, roger peppe <rogpe...@gmail.com> wrote: > >> >> > >> >> > >> >> On Thu, 16 Jan 2020 at 13:57, Ryan Skraba <r...@skraba.com> wrote: > >> >>> > >> >>> Hello! Is it because you are using brew to install avro-tools? I'm > >> >>> not entirely familiar with how it packages the command, but using a > >> >>> direct bash-like solution instead might solve this problem of mixing > >> >>> stdout and stderr. This could be the simplest (and right) solution > >> >>> for piping. > >> >> > >> >> > >> >> No, I downloaded the jar and am directly running it with "java -jar > ~/other/avro-tools-1.9.1.jar". > >> >> I'm using Ubuntu Linux 18.04 FWIW - the binary comes from Debian > package openjdk-11-jre-headless. > >> >> > >> >> I'm going to try compiling avro-tools myself to investigate but I'm > a total Java ignoramus - wish me luck! > >> >> > >> >>> > >> >>> alias avrotoolx='java -jar > >> >>> > ~/.m2/repository/org/apache/avro/avro-tools/1.9.1/avro-tools-1.9.1.jar' > >> >>> avrotoolx tojson x.out 2> /dev/null > >> >>> > >> >>> (As Fokko mentioned, the 2> /dev/null isn't even necessary -- the > >> >>> warnings and logs should not be piped along with the normal > content.) > >> >>> > >> >>> Otherwise, IIRC, there is no way to disable the first illegal > >> >>> reflective access warning when running in Java 9+, but you can "fix" > >> >>> these module errors, and deactivate the NativeCodeLoader logs with > an > >> >>> explicit log4j.properties: > >> >>> > >> >>> java -Dlog4j.configuration=file:///tmp/log4j.properties --add-opens > >> >>> java.security.jgss/sun.security.krb5=ALL-UNNAMED -jar > >> >>> > ~/.m2/repository/org/apache/avro/avro-tools/1.9.1/avro-tools-1.9.1.jar > >> >>> tojson x.out > >> >> > >> >> > >> >> Thanks for that suggestion! I'm afraid I'm not familiar with log4j > properties files though. What do I need to put in /tmp/log4j.properties to > make this work? > >> >> > >> >>> None of that is particularly satisfactory, but it could be a > >> >>> workaround for your immediate use. > >> >> > >> >> > >> >> Yeah, not ideal, because if something goes wrong, stdout will be > corrupted, but at least some noise should go away :) > >> >> > >> >>> I'd also like to see a more unified experience with the CLI tool for > >> >>> documentation and usage. The current state requires a bit of Avro > >> >>> expertise to use, but it has some functions that would be pretty > >> >>> useful for a user working with Avro data. I raised > >> >>> https://issues.apache.org/jira/browse/AVRO-2688 as an improvement. > >> >>> > >> >>> In my opinion, a schema compatibility tool would be a useful and > >> >>> welcome feature! > >> >> > >> >> > >> >> That would indeed be nice, but in the meantime, is there really > nothing in the avro-tools commands that uses a chosen schema to read a data > file written with some other schema? That would give me what I'm after > currently. > >> >> > >> >> Thanks again for the helpful response. > >> >> > >> >> cheers, > >> >> rog. > >> >> > >> >>> > >> >>> Best regards, Ryan > >> >>> > >> >>> > >> >>> > >> >>> On Thu, Jan 16, 2020 at 12:25 PM roger peppe <rogpe...@gmail.com> > wrote: > >> >>> > > >> >>> > Hi Fokko, > >> >>> > > >> >>> > Thanks for your swift response! > >> >>> > > >> >>> > Stdout and stderr definitely seem to be merged on this platform > at least. Here's a sample: > >> >>> > > >> >>> > % avrotool random --count 1 --schema '"int"' x.out > >> >>> > % avrotool tojson x.out > x.json > >> >>> > % cat x.json > >> >>> > 125140891 > >> >>> > WARNING: An illegal reflective access operation has occurred > >> >>> > WARNING: Illegal reflective access by > org.apache.hadoop.security.authentication.util.KerberosUtil > (file:/home/rog/other/avro-tools-1.9.1.jar) to method > sun.security.krb5.Config.getInstance() > >> >>> > WARNING: Please consider reporting this to the maintainers of > org.apache.hadoop.security.authentication.util.KerberosUtil > >> >>> > WARNING: Use --illegal-access=warn to enable warnings of further > illegal reflective access operations > >> >>> > WARNING: All illegal access operations will be denied in a future > release > >> >>> > 20/01/16 11:00:37 WARN util.NativeCodeLoader: Unable to load > native-hadoop library for your platform... using builtin-java classes where > applicable > >> >>> > % > >> >>> > > >> >>> > I've just verified that it's not a problem with the java > executable itself (I ran a program that printed to System.err and the text > correctly goes to the standard error). > >> >>> > > >> >>> > > Regarding the documentation, the CLI itself contains info on > all the available commands. Also, there are excellent online resources: > https://www.michael-noll.com/blog/2013/03/17/reading-and-writing-avro-files-from-the-command-line/ > Is there anything specific that you're missing? > >> >>> > > >> >>> > There's the single line summary produced for each command by > running "avro-tools" with no arguments, but that's not as much info as I'd > ideally like. For example, it often doesn't say what file format is being > written or read. For some commands, the purpose is not very clear. > >> >>> > > >> >>> > For example the description of the recodec command is "Alters the > codec of a data file". It doesn't describe how it alters it or how one > might configure the alteration parameters. I managed to get some usage help > by passing it more than two parameters (specifying "--help" gives an > exception), but that doesn't provide much more info: > >> >>> > > >> >>> > % avro-tools recodec a b c > >> >>> > Expected at most an input file and output file. > >> >>> > Option Description > >> >>> > ------ ----------- > >> >>> > --codec <String> Compression codec (default: null) > >> >>> > --level <Integer> Compression level (only applies to deflate and > xz) (default: > >> >>> > -1) > >> >>> > > >> >>> > For the record, I'm wondering it might be possible to get > avrotool to tell me if one schema is compatible with another so that I can > check hypotheses about schema-checking in practice without having to write > Java code. > >> >>> > > >> >>> > cheers, > >> >>> > rog. > >> >>> > > >> >>> > > >> >>> > On Thu, 16 Jan 2020 at 10:30, Driesprong, Fokko > <fo...@driesprong.frl> wrote: > >> >>> >> > >> >>> >> Hi Rog, > >> >>> >> > >> >>> >> This is actually a warning produced by the Hadoop library, that > we're using. Please note that htis isn't part of the stdout: > >> >>> >> > >> >>> >> $ find /tmp/tmp > >> >>> >> /tmp/tmp > >> >>> >> /tmp/tmp/._SUCCESS.crc > >> >>> >> > /tmp/tmp/part-00000-9300fba6-ccdd-4ecc-97cb-0c3ae3631be5-c000.avro > >> >>> >> > /tmp/tmp/.part-00000-9300fba6-ccdd-4ecc-97cb-0c3ae3631be5-c000.avro.crc > >> >>> >> /tmp/tmp/_SUCCESS > >> >>> >> > >> >>> >> $ avro-tools tojson > /tmp/tmp/part-00000-9300fba6-ccdd-4ecc-97cb-0c3ae3631be5-c000.avro > >> >>> >> 20/01/16 11:26:10 WARN util.NativeCodeLoader: Unable to load > native-hadoop library for your platform... using builtin-java classes where > applicable > >> >>> >> {"line_of_text":{"string":"Hello"}} > >> >>> >> {"line_of_text":{"string":"World"}} > >> >>> >> > >> >>> >> $ avro-tools tojson > /tmp/tmp/part-00000-9300fba6-ccdd-4ecc-97cb-0c3ae3631be5-c000.avro > > /tmp/tmp/data.json > >> >>> >> 20/01/16 11:26:20 WARN util.NativeCodeLoader: Unable to load > native-hadoop library for your platform... using builtin-java classes where > applicable > >> >>> >> > >> >>> >> $ cat /tmp/tmp/data.json > >> >>> >> {"line_of_text":{"string":"Hello"}} > >> >>> >> {"line_of_text":{"string":"World"}} > >> >>> >> > >> >>> >> So when you pipe the data, it doesn't include the warnings. > >> >>> >> > >> >>> >> Regarding the documentation, the CLI itself contains info on all > the available commands. Also, there are excellent online resources: > https://www.michael-noll.com/blog/2013/03/17/reading-and-writing-avro-files-from-the-command-line/ > Is there anything specific that you're missing? > >> >>> >> > >> >>> >> Hope this helps. > >> >>> >> > >> >>> >> Cheers, Fokko > >> >>> >> > >> >>> >> Op do 16 jan. 2020 om 09:30 schreef roger peppe < > rogpe...@gmail.com>: > >> >>> >>> > >> >>> >>> Hi, > >> >>> >>> > >> >>> >>> I've been trying to use avro-tools to verify Avro > implementations, and I've come across an issue. Perhaps someone here might > be able to help? > >> >>> >>> > >> >>> >>> When I run avro-tools with some subcommands, it prints a bunch > of warnings (see below) to the standard output. Does anyone know a way to > disable this? I'm using openjdk 11.0.5 under Ubuntu 18.04 and avro-tools > 1.9.1. > >> >>> >>> > >> >>> >>> The warnings are somewhat annoying because they can corrupt > output of tools that print to the standard output, such as recodec. > >> >>> >>> > >> >>> >>> Aside: is there any documentation for the commands in > avro-tools? Some seem to have some command-line help (though unfortunately > there doesn't seem to be a standard way of showing it), but often that help > often doesn't describe what the command actually does. > >> >>> >>> > >> >>> >>> Here's the output that I see: > >> >>> >>> > >> >>> >>> WARNING: An illegal reflective access operation has occurred > >> >>> >>> WARNING: Illegal reflective access by > org.apache.hadoop.security.authentication.util.KerberosUtil > (file:/home/rog/other/avro-tools-1.9.1.jar) to method > sun.security.krb5.Config.getInstance() > >> >>> >>> WARNING: Please consider reporting this to the maintainers of > org.apache.hadoop.security.authentication.util.KerberosUtil > >> >>> >>> WARNING: Use --illegal-access=warn to enable warnings of > further illegal reflective access operations > >> >>> >>> WARNING: All illegal access operations will be denied in a > future release > >> >>> >>> 20/01/16 08:12:39 WARN util.NativeCodeLoader: Unable to load > native-hadoop library for your platform... using builtin-java classes where > applicable > >> >>> >>> > >> >>> >>> cheers, > >> >>> >>> rog. > >> >>> >>> >
