How to Send Solr Optimize Command

by Xavier Comments: 1

There are times when you want to optimize your Solr index. But what is optimize and why do I care?

Optimize is similar to when you defragment your hard drive. Solr will create a new index removing any deleted documents. It is simply house keeping at its best.

I usually do a commit from the Admin UI, going to the overview tab. Solr Optimize

 

However, sometimes we might want to do it programatically, a good example being when you have a spell checker configured to build the dictionary on optimize. The url to optimize is very simple, here is an example with my localhost, just replace with your Solr

http://localhost:8983/solr/yourcore/update?stream.body=<optimize><query>*:*</query></optimize>

 

Notice how the # is removed from all REST calls vs when the Admin UI loads.

Happy optimizing!

Easy way to do a Solr Core Reload

by Xavier Comments: 0

Many times have I stopped and restarted Solr to reload a core, yes it is kind of a rookie way as you can always go to the Admin UI, Core Admin and reload Core.

But what if you wanted to have a really fast way of reloading your core?

Just do it via the admin handler!
http://{SOLR IP}:{SOLR PORT}/solr/admin/cores?action=RELOAD&core={CORE NAME}

You can even add it to your code and make a simple call or better yet use SolrNet via the admin functionality found below:

https://github.com/mausch/SolrNet/blob/master/Documentation/Core-admin.md

 

Easiest Way of Issuing Solr Commit Command

by Xavier Comments: 0

There are a couple of ways to trigger a commit command in Solr. The easiest way is via a URL:

http://localhost:8983/solr/collection1/update?commit=true

(Replace localhost:8983 with your Solr url and )

But you can also commit using the Documents option from the Admin UI. Simply navigate to Documents, using this URL:

http://localhost:8983/solr/collection1/documents

And select Solr Command (raw XML orJSON), adding the command

<commit>
true
</commit>

Solr Command

 

 

 

 

 

 

Submit Document! It just works. And if you are using SolrCloud, the command goes to everyone.

Quick Tip: Find Missing Fields in Apache Solr

by Xavier Comments: 0

I had an issue raised because of a mismatch between my document results and my facet counts. The issue is basically that there is a field that is not required and in most cases, the field is added with an empty string – which is ok as empty has a meaning. However in a few cases, the field is not added at all and this is not the expected scenario. So I needed to find out why did this happen, which means finding the document id so that it can be reviewed during indexing.

Oh well..I was tired so I ran a *:* query and got all results… too much text.

Query for all: q=*:*

Added only the two fields that I needed in the fl field so that only those fields that I needed were shown and number of rows to see them all. This was kind of slow and inconvenient.

Query for all with only required fields and all rows: q=*:*&fl=title myfacet&rows=1600

So now I remembered query for missing fields! Just use the – operator on a field name.

Query for documents with missing fields: q=-myfacet:*

Problem solved. Easy as pie!

How to Start a Development Apache Solr

by Xavier Comments: 3

I am preparing for a presentation this month on Solr and SolrNet for the Atlanta .NET User Group.  Solr 5 is already out but I will be running my demos using Solr 4.10. Now that I am starting the preparation process, it really feels so good to know that starting a local Solr is SO EASY. Check out the steps which couldn’t be easier:

– Assuming you already downloaded Solr (here if you haven’t: http://lucene.apache.org/solr/downloads.html)

– Just extract into a folder. Mine is called AtlantaSolr

– Make sure you have Java running. If unsure just type java -version

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– Now navigate to your Solr folder, in my case C:\Dropbox\Public Speaking\AtlantaSolrSolrNet

– Type the magic words java -jar start.jar and let it load.

– Voila! Navigate to localhost:8983/solr

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It couldn’t be easier!

How to change the Solr request handler with SolrNet and ServiceLocator

by Xavier Comments: 1

I am working in a project that sounds like heaven to me. Big company, hundreds of developers, latest technology all around, totally agile and the search is done with Solr and a REST API in C# which of course uses SolrNet (who would think otherwise?)

In any case, spellcheck was enabled and this wreaked havoc whenever servers were rebooted. It seems like SolrCloud has an issue with spellchecking . The problem is that setting spellcheck in /select request handler makes Solr spin its wheels for a long time while starting, and it has been tracked inhttps://issues.apache.org/jira/browse/SOLR-6679. The recommended workaround is to have spell check set up in a different request handler.

But here is the problem. In SolrNet you can’t easily explicitly specify the request handler. It basically uses /select.  The request handler is specified via the Handler property in ISolrQueryExecuter. You can see it in action here:

https://github.com/mausch/SolrNet/blob/master/SolrNet/Impl/SolrQueryExecuter.cs

I checked through many forums and threads to try to get to a solution and here are some of the threads I found:

Changing Handler endpoint in SolrQueryExecuter? https://groups.google.com/forum/?fromgroups=#!searchin/solrnet/handler/solrnet/Kqxn68pU0uo/uG50WSxu_swJ

How can I perform solrnet query in two different request handler? https://groups.google.com/forum/#!topic/solrnet/ZA-bv9dkh_0

Different request handler https://groups.google.com/forum/#!topic/solrnet/SP14XmifcrY

Calling Custom Request Handler https://groups.google.com/forum/#!topic/solrnet/THX-ADS5CLQ

http://stackoverflow.com/questions/13393700/how-we-changes-standard-query-handler

There were many recommendations, among them:

–          Use qt, which the problem is that it is deprecated and I think will not be available in Solr 5. And there is a lot of pushback against qt.

–          Move to CastleWindsor, which is what Eduardo, a friend of mine did last week.  I don’t have enough time to do this. On a really tight schedule.

–          Replace the Handler property in SolrQueryExecuter, which is what was recommended in one of the threads

–          Or Remove() and re Register() the ISolrQueryExecuter

One of the recommendations was modify the Handler this way:

Startup.Init<T>(new SolrConnection("http://localhost:8080/solr"));

var executor = ServiceLocator.Current.GetInstance<ISolrQueryExecuter<T>>() as SolrQueryExecuter<T>;

executor.Handler = "/new";

Which did not work as it did not modify the registered instance. No idea, but if you know how to fix let me know.

So the recommendation from Mauricio Scheffer was to Remove and Reregister, which I did not know how to do but Satish, a very friendly developer, helped me. Here is the solution:

Startup.Init<MyDocument>( “http://localhost:8080/solr”);

var container = ServiceLocator.Current as SolrNet.Utils.Container;

container.Remove<ISolrQueryExecuter<MyDocument>>();

var instance = new SolrQueryExecuter<MyDocument>(container.GetInstance<ISolrAbstractResponseParser<MyDocument>>(), new SolrConnection(“http://localhost:8080/solr”), container.GetInstance<ISolrQuerySerializer>(), container.GetInstance<ISolrFacetQuerySerializer>(), container.GetInstance<ISolrMoreLikeThisHandlerQueryResultsParser<MyDocument>>());

instance.Handler = "/yourhandler";

And this saved my day!

Should I Rename the uniquekey in Solr?

by Xavier Comments: 1

I was asked today if it makes sense to change the name of the default id field in Solr to something else?

Let me explain. You download your Solr, you get it up and running and you start modifying fields in Schema.xml. Currently the uniquekey is called id and it is defined as uniquekey. No harm done in leaving as is. It looks something like what I have below.

<field name=”id” type=”string” indexed=”true” stored=”true” required=”true” multiValued=”false” />

….

<uniqueKey>id</uniqueKey>

At first it may seem like it doesn’t matter what it is actually called, however if you think about it a little bit more it may make sense to change it.

Why?

Simple. Because id, by being the default value may be used in other locations, even in sample code and it may have been used for specific purposes or in ways that you are not aware of.

So by changing it, you are forcing yourself to be aware of where the id field is being used. It is not a huge difference, but the devil is in the details.

Something as easy as changing it to look like this is more than enough.

<field name=”itemid” type=”string” indexed=”true” stored=”true” required=”true” multiValued=”false” />

….

<uniqueKey>itemid</uniqueKey>

Want a more precise example? Run SolrNet’s sample app and just change the name of the uniquekey. Tell me how it went!

The NIH Syndrome in Action: Calling Solr’s REST API

by Xavier Comments: 0

As I mentioned in my previous post, I was having a chat with a search architect on C# and Solr and he was telling me how they were going to call Solr using its REST API, which IMHO is not the best way to go.

I recommended SolrNet and I stick with this recommendation because you do not want to reinvent the wheel. SolrNet has been built over the course of several years, there are plenty of people using it and they have had the time to understand the functionality that Solr provides and code it accordingly. The problem that you will face if you implement everything via REST calls is that you need to take into consideration all possible scenarios, which in a lot of cases does not happen, And that’s when exceptions start to occur.

In some cases it is not possible to use a library as there may be legal implications. But in other cases it is because of the NIH syndrome, or the not invented here syndrome.

Sometimes teams prefer to have everything created in house. In my opinion that may apply pretty well if you have a closed library as you are at the mercy of the company’s support and sometimes even their ability to profit and therefore continue to exist.

But if it is open source, like SolrNet, then don’t be afraid. You are in control, you can modify the code if need be – as with any open source, of course following the licensing terms – and definitively you can benefit from the experience of many others that have traveled the same road you are currently on.

But of course, be nice. If you make an improvement, please contribute back to the SolrNet community. Then we all mutually benefit.

Using Solr from C# Made Dead Easy with SolrNet

by Xavier Comments: 2

I was having a conversation with an solutions architect a few days ago about a specific Solr project with .NET. He was telling me some of the details of what they were going to build, how they were going to call Solr’s REST API for querying and ….

Stop the press… Stop right there… I said….

You are going to call Solr’s REST API? Really? The fact that Solr has a REST API is massively useful, but why do you want to reinvent the wheel.

If you want to use Solr from .NET, I explained, the best way is to use SolrNet(https://github.com/mausch/SolrNet). SolrNet is an Apache Solr client for .Net that allows for you to use Solr from .NET in a super easy and efficient way. It abstracts Solr in such an easy way that you basically just create a POCO object (Plain Old Clr Object – not to wrongly called Plain Old C# Object as many people do) and presto, you have functions to Add, Delete, Commit and more. Let me show you a small sample I built about a week ago in literally just a few minutes to index a few thousand mails from Pluralsight’s (the best online training resource available IMHO – and yes I am a bit biased here!) author distribution list.

To create this demo, where I indexed about 4k emails I did the following

– Download Solr, 4.10 at the time [takes a few minutes to download]

– Clone collection1 and rename it authorslist, don’t forget to change the collection name

– Change in schema.xml so that you have the following fields (and remember this is just a quick and dirty example that I wanted to show how provide a searchable index of all author mails inside a Wordpress site. Looks like this:

<field name=”itemid” type=”string” indexed=”true” stored=”true” required=”true” multiValued=”false” />
<field name=”subject” type=”text_general” indexed=”true” stored=”true”/>
<field name=”sent” type=”date” indexed=”true” stored=”true” omitNorms=”true”/>
<field name=”sendername” type=”string” indexed=”true” stored=”true” multiValued=”false”/>
<field name=”recipients” type=”string” indexed=”true” stored=”true” multiValued=”true”/>
<field name=”body” type=”text_general” indexed=”true” stored=”true”/>
<field name=”htmlbody” type=”text_general” indexed=”false” stored=”true”/>

– Make itemid uniquekey instead of id

– Modify solrconfig.xml to add a new requesthandler, so that I can play a bit with facets and weights, nothing out of the ordinary

– And now to index the mails I just wrote a few lines of code to read from my Outlook, using the Office Primary Interop Assemblies (known as PIAs) in a console application

– Add SolrNet to the console app

– Create a POCO object to represent whatever I added to the schema. It should look like this. Please notice the attributes, which is what tells SolrNet what it is representing in Solr. This is my POCO object:

public class MailSolr {

[SolrUniqueKey(“itemid”)]
public string ItemId { get; set; }

[SolrField(“subject”)]
public string Subject { get; set; }

[SolrField(“sent”)]
public DateTime Sent { get; set; }

[SolrField(“sendername”)]
public string SenderName { get; set; }

[SolrField(“recipients”)]
public ICollection Recipients { get; set; }

[SolrField(“body”)]
public string Body { get; set; }

[SolrField(“htmlbody”)]
public string HtmlBody { get; set; }
}

– And write the following lines to index

ISolrOperations solr = GetSolr();
int it = 0;
foreach (Microsoft.Office.Interop.Outlook.MailItem i in lM)
{
it++;
MailSolr m = new MailSolr();
m.ItemId = i.EntryID;
m.Subject = i.Subject;
m.Sent = i.SentOn;
m.SenderName = i.SenderName;
m.Body = i.Body;
m.HtmlBody = i.HTMLBody;

solr.Add(m);
}
solr.Commit();

As you can see adding a document with SolrNet is dead easy. Simply connect to Solr, create a new instance of your POCO object, solr.Add() and solr.Commit(). How much easier would you want it to be?

Next Tuesday I will talk about the NIH syndrome (not invented here) around SolrNet.

Five ways meetings suck and how to make them rock!

by Xavier Comments: 2

Meetings are a double edge sword. On one hand they are very useful for brainstorming, communication within and between teams and in general when used appropriately it sparks collaboration; moving projects forward.

The problem lies when meetings are misused or abused which sadly sometimes tends to happen more often than not. And that’s why I want to tell you 5 reasons why meetings suck and how to make them rock!

#1 People use them to keep busy vs being productive: I’ve seen many times how people set up meetings because for them going to the meeting is the work. Even worse, a lot of meetings end with “let’s set up another meeting to continue the discussion”. This is very common among Project Managers or Product Managers. Just as a fun mental exercise, take a couple of minutes and think if you know a few. I do.

How to deal with it: Make sure that every meeting that you attend or control over has a real and very clear objective. Even more, make sure that it is important that this meeting takes place. If the objective is not important or required, then simply defer it until it is the right time.

#2 A 1 hour meeting is not a 1 hour meeting: Have you ever been in a 1 hour meeting with 15 other folks and wondered how much work you actually have to get done instead of just sit there waiting for the 1 hour mark or your 2 minute turn to talk. Also, they guy next to you seems to be thinking the same while playing Candy Crush or in the best case answering emails? Well it is much worse than that. A 1 hour meeting with 16 people is actually 2 man days of work lost forever, gone in time. I shiver just to think of how many dollars are wasted because of overcrowded meetings!

How to deal with it: Not everyone needs to be invited to every meeting. Make sure each person has a clear and known reason of why they are there and (friendly) kick out of the room anyone that doesn’t. Also, as the old adage says, “divide and conquer”. A very broad topic where too many people are involved can be broken down into smaller chunks with smaller groups. You only need one person to coordinate among the teams, and 1 is always much better than a committee. This is very common with Scrums that get abused and end up looking more like office parties. Bonus points if people bring food as that distracts even further!

#3 Meetings without agenda: Another reason why some meetings take much longer than expected is that there isn’t a clear agenda and objective. This leads to endless talking, going on tangents and again scheduling new meetings to continue the conversation. People also confuse a meeting agenda with just the subject of the meeting. For example, “Discussion on data” is not clear, it is broad and subjective. This scenario goes hand in hand when overall project vision is not very clear or there are many unknowns.

How to deal with it: Create a clear agenda with well defined points and if possible, use my favorite feature of Scrum: timebox. Parkinson’s law is the adage that “work expands so as to fill the time available for its completion” and this applies very well to meetings. If you don’t have a limit, people will use all time possible for a discussion. Timebox in a reasonable way and you may see wonderful results. And if the issue is overall project vision, try planning shorter term until there is a clearer view of the road ahead.

#4 Interruptions break flow for makers: If you work hard on improving yourself you are probably familiar with the concept of “flow”, but if you are not then interiorize this: “flow is the mental state of operation in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity”. This is when you get a lot done. Developers usually experience this without knowing when “time flies”. But in reality what happened was that the brain was fully focused and engaged in a task with potentially wonderful results.

There is something else that you should be familiar with that is the “Maker’s Schedule, Manager’s Schedule”. Now let me explain. If you are a maker, i.e. programmer, you work most likely in large chunks of time, for example from 8 am to noon. During that time you focus on solving a problem and if you are interrupted, it may take up to 15 minutes to pick up where you left off. This means that if there are multiple meetings throughout the day, your maker’s schedule gets broken down into many small chunks that do not allow for focused full involvement into a task. I worked on multiple projects in Microsoft’s main campus in Seattle and it seemed like everyone in this particular division worked in 1 hour intervals which wreaked havoc on development work. Culprit: too many (project) managers in the same building. Real development took place somewhere else.

How to deal with the managers’s schedule:

Manager’s usually have smaller chunks of work that can be broken down into 1 hour slots, hence their impulse to “book meetings with the team to catch up”. They may have the best intentions, but this usually has a negative impact. Even worse, managers are higher in the food chain so let me ask you this, when was the last time that you simply cancelled a meeting with your boss because he was interrupting you?

How to deal with the maker’s schedule: The first step is for the manager to understand the impact he is having on his whole team with constant interruptions. This sometimes requires the maker to approach the manager and explain the implications of the constant interruptions. Then the manager should aim to schedule (required) meetings when they cause the least impact, which can be near start, noon or end of day. Also, use asynchronous communication. This sounds complex, but it is basically email, chat or even better, something like Jira to manage the makers progress.

#5 Another chance for talkers to take the stage, not doers: This is a very tricky one as it requires a leader that is aware of the capabilities and responsibilities of the team members attending the meeting. The problem usually lies in that human personalities are extremely different so some people tend to talk a lot while others prefer silence. And talking is not directly proportional to doing. Someone might talk a lot and do very little and the actual guy doing the work will just sit there and listen. This creates then an unbalanced and biased view as not all of the involved parties will communicate appropriately and the outcome of the meeting might not be the best.

How to deal with it: It is the meeting organizer’s responsibility to understand what is the involvement of each one of the parties invited to the meeting in respect to the meeting agenda. Then ask questions specifically on each one of the topics to get the correct information and help obtain the best possible outcome for the meeting.

In summary meetings can help your team leap forward. Just remember to schedule meetings only when absolutely required instead of as a way to keep busy, inviting only those that are definitively required, with a very clear agenda and objective, at times where they don’t interrupt the maker’s schedule and guiding the meeting to make sure that everyone contributes their share.

Any other recommendations?