Assuming we're going to write all errors to a single error topic, I think
it makes sense to agree on an error message schema and handle errors across
the 3 different topologies in the same way with a single implementation.
The implementation in ParserBolt (ErrorUtils.handleError) produces the most
verbose error object so I think it's a good candidate for the single
implementation. Here is the message structure it currently produces:
{
"exception": "java.lang.Exception: there was an error",
"hostname": "host",
"stack": "java.lang.Exception: ...",
"time": 1485295416563,
"message": "there was an error",
"rawMessage": "raw message",
"rawMessage_bytes": [],
"source.type": "bro_error"
}
>From our discussion so far we need to add a couple fields: an error type
and hash id. Adding these to the message looks like:
{
"exception": "java.lang.Exception: there was an error",
"hostname": "host",
"stack": "java.lang.Exception: ...",
"time": 1485295416563,
"message": "there was an error",
"rawMessage": "raw message",
"rawMessage_bytes": [],
"source.type": "bro_error",
"error.type": "parser_error",
"rawMessage_hash": "dde41b9920954f94066daf6291fb58a9"
}
We should also consider expanding the error types I listed earlier.
Instead of just having "indexing_error" we could have
"elasticsearch_indexing_error", "hdfs_indexing_error" and so on.
Jon, if an exception happens in an enrichment or threat intel bolt the
message is passed along with no error thrown (only logged). Everywhere
else I'm having trouble identifying specific fields that should be hashed.
Would hashing the message in every case be acceptable? Do you know of a
place where we could hash a field instead? On the topic of exceptions in
enrichments, are we ok with an error only being logged and not added to the
message or emitted to the error queue?
On Tue, Jan 24, 2017 at 3:10 PM, Ryan Merriman <merrim...@gmail.com> wrote:
> That use case makes sense to me. I don't think it will require that much
> additional effort either.
>
> On Tue, Jan 24, 2017 at 1:02 PM, zeo...@gmail.com <zeo...@gmail.com>
> wrote:
>
>> Regarding error vs validation - Either way I'm not very concerned. I
>> initially assumed they would be combined and agree with that approach, but
>> splitting them out isn't a very big deal to me either.
>>
>> Re: Ryan. Yes, exactly. In the case of a parser issue (or anywhere else
>> where it's not possible to pick out the exact thing causing the issue) it
>> would be a hash of the complete message.
>>
>> Regarding the architecture, I mostly agree with James except that I think
>> step 3 needs to also be able to somehow group errors via the original
>> data (identify
>> replays, identify repeat issues with data in a specific field, issues with
>> consistently different data, etc.). This is essentially the first step of
>> troubleshooting, which I assume you are doing if you're looking at the
>> error dashboard.
>>
>> If the hash gets moved out of the initial implementation, I'm fairly
>> certain you lose this ability. The point here isn't to handle long fields
>> (although that's a benefit of this approach), it's to attach a unique
>> identifier to the error/validation issue message that links it to the
>> original problem. I'd be happy to consider alternative solutions to this
>> problem (for instance, actually sending across the data itself) I just
>> haven't been able to think of another way to do this that I like better.
>>
>> Jon
>>
>> On Tue, Jan 24, 2017 at 1:13 PM Ryan Merriman <merrim...@gmail.com>
>> wrote:
>>
>> > We also need a JIRA for any install/Ansible/MPack work needed.
>> >
>> > On Tue, Jan 24, 2017 at 12:06 PM, James Sirota <jsir...@apache.org>
>> wrote:
>> >
>> > > Now that I had some time to think about it I would collapse all error
>> and
>> > > validation topics into one. We can differentiate between different
>> views
>> > > of the data (split by error source etc) via Kibana dashboards. I
>> would
>> > > implement this feature incrementally. First I would modify all the
>> bolts
>> > > to log to a single topic. Second, I would get the error indexing
>> done by
>> > > attaching the indexing topology to the error topic. Third I would
>> create
>> > > the necessary dashboards to view errors and validation failures by
>> > source.
>> > > Lastly, I would file a follow-on JIRA to introduce hashing of errors
>> or
>> > > fields that are too long. It seems like a separate feature that we
>> need
>> > to
>> > > think through. We may need a stellar function around that.
>> > >
>> > > Thanks,
>> > > James
>> > >
>> > > 24.01.2017, 10:25, "Ryan Merriman" <merrim...@gmail.com>:
>> > > > I understand what Jon is talking about. He's proposing we hash the
>> > value
>> > > > that caused the error, not necessarily the error message itself.
>> For an
>> > > > enrichment this is easy. Just pass along the field value that failed
>> > > > enrichment. For other cases the field that caused the error may not
>> be
>> > so
>> > > > obvious. Take parser validation for example. The message is
>> validated
>> > as
>> > > > a whole and it may not be easy to determine which field is the
>> cause.
>> > In
>> > > > that case would a hash of the whole message work?
>> > > >
>> > > > There is a broader architectural discussion that needs to happen
>> before
>> > > we
>> > > > can implement this. Currently we have an indexing topology that
>> reads
>> > > from
>> > > > 1 topic and writes messages to ES but errors are written to several
>> > > > different topics:
>> > > >
>> > > > - parser_error
>> > > > - parser_invalid
>> > > > - enrichments_error
>> > > > - threatintel_error
>> > > > - indexing_error
>> > > >
>> > > > I can see 4 possible approaches to implementing this:
>> > > >
>> > > > 1. Create an index topology for each error topic
>> > > > 1. Good because we can easily reuse the indexing topology and
>> > would
>> > > > require the least development effort
>> > > > 2. Bad because it would consume a lot of extra worker slots
>> > > > 2. Move the topic name into the error JSON message as a new
>> > > "error_type"
>> > > > field and write all messages to the indexing topic
>> > > > 1. Good because we don't need to create a new topology
>> > > > 2. Bad because we would be flowing data and errors through the
>> > same
>> > > > topology. A spike in errors could affect message indexing.
>> > > > 3. Compromise between 1 and 2. Create another indexing topology
>> that
>> > > is
>> > > > dedicated to indexing errors. Move the topic name into the error
>> > JSON
>> > > > message as a new "error_type" field and write all errors to a
>> single
>> > > error
>> > > > topic.
>> > > > 4. Write a completely new topology with multiple spouts (1 for
>> each
>> > > > error type listed above) that all feed into a single
>> > > BulkMessageWriterBolt.
>> > > > 1. Good because the current topologies would not need to
>> change
>> > > > 2. Bad because it would require the most development effort,
>> > would
>> > > > not reuse existing topologies and takes up more worker slots
>> > than 3
>> > > >
>> > > > Are there other approaches I haven't thought of? I think 1 and 2 are
>> > off
>> > > > the table because they are shortcuts and not good long-term
>> solutions.
>> > 3
>> > > > would be my choice because it introduces less complexity than 4.
>> > > Thoughts?
>> > > >
>> > > > Ryan
>> > > >
>> > > > On Mon, Jan 23, 2017 at 5:44 PM, zeo...@gmail.com <zeo...@gmail.com
>> >
>> > > wrote:
>> > > >
>> > > >> In that case the hash would be of the value in the IP field, such
>> as
>> > > >> sha3(8.8.8.8).
>> > > >>
>> > > >> Jon
>> > > >>
>> > > >> On Mon, Jan 23, 2017, 6:41 PM James Sirota <jsir...@apache.org>
>> > wrote:
>> > > >>
>> > > >> > Jon,
>> > > >> >
>> > > >> > I am still not entirely following why we would want to use
>> hashing.
>> > > For
>> > > >> > example if my error is "Your IP field is invalid and failed
>> > > validation"
>> > > >> > hashing this error string will always result in the same hash.
>> Why
>> > > not
>> > > >> > just use the actual error string? Can you provide an example
>> where
>> > > you
>> > > >> > would use it?
>> > > >> >
>> > > >> > Thanks,
>> > > >> > James
>> > > >> >
>> > > >> > 23.01.2017, 16:29, "zeo...@gmail.com" <zeo...@gmail.com>:
>> > > >> > > For 1 - I'm good with that.
>> > > >> > >
>> > > >> > > I'm talking about hashing the relevant content itself not the
>> > > error.
>> > > >> Some
>> > > >> > > benefits are (1) minimize load on search index (there's
>> minimal
>> > > benefit
>> > > >> > in
>> > > >> > > spending the CPU and disk to keep it at full fidelity
>> (tokenize
>> > and
>> > > >> > store))
>> > > >> > > (2) provide something to key on for dashboards (assuming a
>> good
>> > > hash
>> > > >> > > algorithm that avoids collisions and is second preimage
>> > resistant)
>> > > and
>> > > >> > (3)
>> > > >> > > specific to errors, if the issue is that it failed to index, a
>> > hash
>> > > >> gives
>> > > >> > > us some protection that the issue will not occur twice.
>> > > >> > >
>> > > >> > > Jon
>> > > >> > >
>> > > >> > > On Mon, Jan 23, 2017, 2:47 PM James Sirota <
>> jsir...@apache.org>
>> > > wrote:
>> > > >> > >
>> > > >> > > Jon,
>> > > >> > >
>> > > >> > > With regards to 1, collapsing to a single dashboard for each
>> > would
>> > > be
>> > > >> > > fine. So we would have one error index and one "failed to
>> > validate"
>> > > >> > > index. The distinction is that errors would be things that
>> went
>> > > wrong
>> > > >> > > during stream processing (failed to parse, etc...), while
>> > > validation
>> > > >> > > failures are messages that explicitly failed stellar
>> > > validation/schema
>> > > >> > > enforcement. There should be relatively few of the second
>> type.
>> > > >> > >
>> > > >> > > With respect to 3, why do you want the error hashed? Why not
>> just
>> > > >> search
>> > > >> > > for the error text?
>> > > >> > >
>> > > >> > > Thanks,
>> > > >> > > James
>> > > >> > >
>> > > >> > > 20.01.2017, 14:01, "zeo...@gmail.com" <zeo...@gmail.com>:
>> > > >> > >> As someone who currently fills the platform engineer role, I
>> can
>> > > give
>> > > >> > this
>> > > >> > >> idea a huge +1. My thoughts:
>> > > >> > >>
>> > > >> > >> 1. I think it depends on exactly what data is pushed into the
>> > > index
>> > > >> > (#3).
>> > > >> > >> However, assuming the errors you proposed recording, I can't
>> see
>> > > huge
>> > > >> > >> benefits to having more than one dashboard. I would be happy
>> to
>> > be
>> > > >> > >> persuaded otherwise.
>> > > >> > >>
>> > > >> > >> 2. I would say yes, storing the errors in HDFS in addition to
>> > > >> indexing
>> > > >> > is
>> > > >> > >> a good thing. Using METRON-510
>> > > >> > >> <https://issues.apache.org/jira/browse/METRON-510> as a case
>> > > study,
>> > > >> > there
>> > > >> > >> is the potential in this environment for attacker-controlled
>> > data
>> > > to
>> > > >> > >
>> > > >> > > result
>> > > >> > >> in processing errors which could be a method of evading
>> security
>> > > >> > >> monitoring. Once an attack is identified, the long term HDFS
>> > > storage
>> > > >> > would
>> > > >> > >> allow better historical analysis for low-and-slow/persistent
>> > > attacks
>> > > >> > (I'm
>> > > >> > >> thinking of a method of data exfil that also won't
>> successfully
>> > > get
>> > > >> > stored
>> > > >> > >> in Lucene, but is hard to identify over a short period of
>> time).
>> > > >> > >> - Along this line, I think that there are various parts of
>> > Metron
>> > > >> > (this
>> > > >> > >> included) which could benefit from having method of
>> configuring
>> > > data
>> > > >> > aging
>> > > >> > >> by bucket in HDFS (Following Nick's comments here
>> > > >> > >> <https://issues.apache.org/jira/browse/METRON-477>).
>> > > >> > >>
>> > > >> > >> 3. I would potentially add a hash of the content that failed
>> > > >> > validation to
>> > > >> > >> help identify repeats over time with less of a concern that
>> > you'd
>> > > >> have
>> > > >> > >
>> > > >> > > back
>> > > >> > >> to back failures (i.e. instead of storing the value itself).
>> > > >> > Additionally,
>> > > >> > >> I think it's helpful to be able to search all times there
>> was an
>> > > >> > indexing
>> > > >> > >> error (instead of it hitting the catch-all).
>> > > >> > >>
>> > > >> > >> Jon
>> > > >> > >>
>> > > >> > >> On Fri, Jan 20, 2017 at 1:17 PM James Sirota <
>> > jsir...@apache.org>
>> > > >> > wrote:
>> > > >> > >>
>> > > >> > >> We already have a capability to capture bolt errors and
>> > validation
>> > > >> > errors
>> > > >> > >> and pipe them into a Kafka topic. I want to propose that we
>> > > attach a
>> > > >> > >> writer topology to the error and validation failed kafka
>> topics
>> > so
>> > > >> > that we
>> > > >> > >> can (a) create a new ES index for these errors and (b)
>> create a
>> > > new
>> > > >> > Kibana
>> > > >> > >> dashboard to visualize them. The benefit would be that errors
>> > and
>> > > >> > >> validation failures would be easier to see and analyze.
>> > > >> > >>
>> > > >> > >> I am seeking feedback on the following:
>> > > >> > >>
>> > > >> > >> - How granular would we want this feature to be? Think we
>> would
>> > > want
>> > > >> > one
>> > > >> > >> index/dashboard per source? Or would it be better to collapse
>> > > >> > everything
>> > > >> > >> into the same index?
>> > > >> > >> - Do we care about storing these errors in HDFS as well? Or
>> is
>> > > >> indexing
>> > > >> > >> them enough?
>> > > >> > >> - What types of errors should we record? I am proposing:
>> > > >> > >>
>> > > >> > >> For error reporting:
>> > > >> > >> --Message failed to parse
>> > > >> > >> --Enrichment failed to enrich
>> > > >> > >> --Threat intel feed failures
>> > > >> > >> --Generic catch-all for all other errors
>> > > >> > >>
>> > > >> > >> For validation reporting:
>> > > >> > >> --What part of message failed validation
>> > > >> > >> --What stellar validator caused the failure
>> > > >> > >>
>> > > >> > >> -------------------
>> > > >> > >> Thank you,
>> > > >> > >>
>> > > >> > >> James Sirota
>> > > >> > >> PPMC- Apache Metron (Incubating)
>> > > >> > >> jsirota AT apache DOT org
>> > > >> > >>
>> > > >> > >> --
>> > > >> > >>
>> > > >> > >> Jon
>> > > >> > >>
>> > > >> > >> Sent from my mobile device
>> > > >> > >
>> > > >> > > -------------------
>> > > >> > > Thank you,
>> > > >> > >
>> > > >> > > James Sirota
>> > > >> > > PPMC- Apache Metron (Incubating)
>> > > >> > > jsirota AT apache DOT org
>> > > >> > >
>> > > >> > > --
>> > > >> > >
>> > > >> > > Jon
>> > > >> > >
>> > > >> > > Sent from my mobile device
>> > > >> >
>> > > >> > -------------------
>> > > >> > Thank you,
>> > > >> >
>> > > >> > James Sirota
>> > > >> > PPMC- Apache Metron (Incubating)
>> > > >> > jsirota AT apache DOT org
>> > > >> >
>> > > >> --
>> > > >>
>> > > >> Jon
>> > > >>
>> > > >> Sent from my mobile device
>> > >
>> > > -------------------
>> > > Thank you,
>> > >
>> > > James Sirota
>> > > PPMC- Apache Metron (Incubating)
>> > > jsirota AT apache DOT org
>> > >
>> >
>> --
>>
>> Jon
>>
>> Sent from my mobile device
>>
>
>
