Full Stack Me

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Here it is, ASICS GlideRide - a consumer-friendly version of the truly innovative ASICS MetaRide, a result of more than two years of R&D from the famous Japanese brand. Hard to argue, they loo stunning and eye-catching, especially with that extremely high stack of roughly 30mm at the heel and 25mm at the forepart. The shoe upper is made of a breathable fabric, it looks and feels quite strong and solid -- the brand is well-known for producing a quality mesh, and this pair doesn’t seem to disappoint. The outsole is basically just a thin layer of rubber, implemented in a way of a band that goes on the left & right parts. It feels extremely thin, especially for the long-distance running shoe and I would just hope it lasts long enough. To figure out how these shoes actually perform on the road, I made two separate tests in them. For the first one, I made a couple of 400m sprint reps. Of course, they still stay on the heavy side, but they don’t feel anyhow bulky or huge. It can take some time to get used to the high profile of 3cm, but 70-75sec per 400m is perfectly doable. For another test, I took them for a longer run, and in the 20K I was aiming for a negative split as I usually do, also doing some occasional sprints in between. Running with GlideRide feels very smooth from the beginning, they don’t feel big or bulky at all. Compared to the speed strides, this extra weight is not so noticeable. Interestingly, because of the high profile & lifted forepart, the shoe facilitates the rolling motion, so the ankles now need to flex less, which typically means you save more energy in the muscles. This should be especially valuable for the longer runs like half or full marathons and beyond. The only remaining concern would be an extra weight to carry. In the end, I've got generally a positive impression from the shoes, and still wear them in day to day runs. Simply put, ASICS GlideRide is your comfy mileage builder that also saves you some energy on the longer run. #asics #glideride #asicsglideride #shoesreview #runningshoes #running #review #trainers #fab #fullstackme As always, check out my blog for the complete detailed review. (at Oxford, Oxfordshire) https://www.instagram.com/p/B7tv1ufjmao/?igshid=1uq8ykup8mvw2

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Race review: Runfest Richmond Marathon (15/09/2019). Alright, so this was my first marathon in the UK. Having done an HM in 1:33 this spring and doing another round of training during summer, I was aiming for sub-3:00 ideally, or, closer to reality, anything between 3:00 and 3:10 at very last. Four weeks back before the race, I passed my peak of 110 km a week and started tapering, reducing mileage & adjusting the nutrition. The week before the race was quite light, though looking back I think I could make it even lighter. On race day, I felt super excited and full of energy. This played a bad joke as I took the front group of runners aiming for sub-3:00. Many of them began way too fast, so I quickly reached my LT since I was heroically trying to keep up and bridge the gaps. Wish I had that energy after 30th km when 3:00 pacemaker took over me, and here I made another mistake trying to follow the pace group, which was obviously running faster than what I could afford at that point. This falsy move made me dying last ~5-7kms, all the way to the not so glorious finish. 3:05 in the end: thanks to some advantage I've built up in the beginning, but still could be better, live and learn. Organisation was great (despite the usual lack of parking in London), so were the spectacular Kew Gardens & Richmond Park. #marathon #running #london #richmond #runfest #racereport #racereview #firstmarathon #marathonuk #olddeerpark #kewgardens As always, don't forget to check out the complete report in my blog. (at Kew Gardens) https://www.instagram.com/p/B63qdHjD3A8/?igshid=wukwh2q32wkz

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ASICS GlideRide running shoes review -- is it a worthy energy saving running shoe for long distances?

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Some races are full of fun and joy, others could happen to be hard. The London Hackney Half-marathon from Virgin Sport was both at the same time. It was really fun but the toughest race for me, to the moment; after all, it was the first half-marathon for me.

Preparing to the race

And since it was the first one, I prepared a lot for it, at least I thought so. This April and March were record-breaking in terms of weekly mileage: from average 30k a week, it went up to 40-45 at the beginning of spring and hit whopping 60k to the end of April. I also made my PB on Oxford’s Parkrun as well as made a decent 1:40:00 negative-split workout with nearly 20k in one go. The race took place on 19 May, and I reserved about two weeks of a good trimming and decreased the intensity of the exercises.

Overall I felt quite prepared, despite a little logistical complication that I had to go to London a day before and stay a night at the hotel. It would be wrong to say that exactly this factor played a bad joke with me, but I definitely underestimated how tiring it could be: to take a train from Oxford, then find the hotel in outskirts of Hackney borough, then try to get asleep with other hotel residents not being quite keen on waking up early tomorrow and therefore playing, drinking & having fun on Saturday night, and finally, wake up at 6AM to get a quick breakfast, shot of coffee and a warm-up to the start village. But here we go.

The race and its organisation

Numbers first: there were more than 16,000 participants (if any trust to the official results), but definitely much more people overall participated in this event, just check out this for details: blog.virginsport.com/2019/05/15/hackneyhalf-is-going-plastic-free. Without any doubt, it was the biggest race in my modest running career, so far.

Nevertheless, the race was very well organised, as well as the starting village. Perfect timing, very spacious and well accessible area, all necessary facilities and what not. The course was very flat: just some rolling hills and a couple of bridges, which is absolutely typical for London. My Garmin watch measured only about 67m of elevation for the entire race. Here is the official course map, by the way:

Image is a courtesy of Virgin Sports

The runners were assigned a starting gate letter and were informed in advance about an approximate time of their gate to open & cross the start line.

And here was my second fault: I have totally forgotten what was the estimated race time I registered to the race. Eventually, it appeared that I was placed somewhere around 2:00:00, with my planned 1:35:00-1:30:00. What is more, I haven’t even thought it mattered to me. Before we started running. Before I actually realised that I have to overtake every single person in front of me, just to run my comfortable pace. But, of course, it was too late, so the first half of the “half” I was in a rush trying to get to the front and meet the group of interest to run my planned ~4:20min/km.

Needless to say, these extra movements had a cost, and to the middle of the race I was behind my planned time, and had to go faster. Got to the red zone before I actually wanted. Got starving for oxygen & glucose and therefore suffered last mile. My perfectly trained negative-split style didn’t work for me. The locals representing Hackney’s community did a great job, I honestly appreciated their cheerful and welcoming support.

Surprisingly, the results that were sent to me nearly instantaneously (they appeared on my mobile literally when I got it back from the baggage drop) were much better than I could have hoped for. 1:33:31. Right within the goal’s limits.

Here is my Strava track after the race, with detailed splits and HR: https://www.strava.com/activities/2380220358.

What can be improved

If you’d ask me, I’d take this question personally -- the preparation plan, logistics of getting to the start village and the race tactics. Not so much for the organisers though: I think they did their job really well. Managing such a crowd isn’t an easy task, and the overall atmosphere of fun & celebration of running strongly stayed in the air. Maybe some little things like shuttle buses from London train stations could help at some point. Otherwise, Virgin Sports deserve big thanks and a great portion of respect.

Originally posted at https://fullstackme.co.uk/sports/how-did-it-go-hackney-half-marathon-2019

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Your stunning high-profile comfy shoes for easy mileage building. Full in-depth review of ASICS GlideRide running shoes.

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How To Read Lined JSON files with Java 8

Came across this, seeming trivial at a glance, task of parsing a relatively well-formatted data feed just recently. Sure, you may say, what could be easier than parsing a JSON format given that there are plenty of tools for that, especially for Java? Well, sorry, not exactly JSON... In effect, compared to other unstructured data sources I previously worked with, this feed used a lined JSON format (i.e. IJSON). Example:

{“id”: “us-cia-world-leaders.bc0...”, “type”: “individual”, ...} {“id”: “us-cia-world-leaders.924...”, “type”: “entity”, ...} {...}

Even though this format is widely used, mainstream JSON parsers such as Jackson cannot handle this structure since it’s not a valid JSON file. Looks like we have a little problem here?

Tackling IJSON with Java

A quick solution is to simply read the lined JSON file line by line and transform each line to a POJO entry. Combined with streamed input readers, the lined JSON format appeared to be more efficacious than the “classic” JSON, merely because we no longer need to preload the entire structure in memory and then transform it. With 30Mb+ files, the performance benefits are evidently noticeable.

The below code snippet illustrates how this can be achieved:

import com.fasterxml.jackson.databind.ObjectMapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.*; import java.util.Objects; import java.util.concurrent.atomic.AtomicInteger; import java.util.function.Consumer; import java.util.stream.Stream; /** * Simple streamed reader to go through Lined JSON files, convert each line to POJO entry * and perform a specified action on every row. * @author Vladimir Salin */ public class LineBasedJsonReader {    private static final Logger log = LoggerFactory.getLogger(LineBasedJsonReader.class);    private ObjectMapper objectMapper;    public LineBasedJsonReader(ObjectMapper objectMapper) {        this.objectMapper = objectMapper;    }    /**     * Parses a provided input in a streamed way. Converts each line in it     * (which is supposed to be a JSON) to a specified POJO class     * and performs an action provided as a Java 8 Consumer.     *     * @param stream lined JSON input     * @param entryClass POJO class to convert JSON to     * @param consumer action to perform on each entry     * @return number of rows read     */    public int parseAsStream(final InputStream stream, final Class entryClass, final Consumer<? super Object> consumer) {        long start = System.currentTimeMillis();        final AtomicInteger total = new AtomicInteger(0);        final AtomicInteger failed = new AtomicInteger(0);        try (Stream<String> lines = new BufferedReader(new InputStreamReader(stream)).lines()) {            lines                    .map(line -> {                        try {                            total.incrementAndGet();                            return objectMapper.readerFor(entryClass).readValue(line);                        } catch (IOException e) {                            log.error("Failed to parse a line {}. Reason: {}", total.get()-1, e.getMessage());                            log.debug("Stacktrace: ", e);                            failed.incrementAndGet();                            return null;                        }                    })                    .filter(Objects::nonNull)                    .forEach(consumer);        }        long took = System.currentTimeMillis() - start;        log.info("Parsed {} lines with {} failures. Took {}ms", total.get(), failed.get(), took);        return total.get() - failed.get();    } }

As you can see, we simply need to pass a source as an InputStream, a POJO class for the JSON we want to parse to, a Java 8 Consumer to act on each parsed row, and that’s it. The above is just a simple snippet for illustrative purposes. In a production environment, one should add more robust error handling.

So why Lined JSON?

Indeed, with these numerous JSON parsing tools, why the heck someone decided to go Lined JSON? Is it any fancy writing every single line in this JSON-y object format?

Actually, yes, it is fancy. Just think of it for a second -- you read the line and get a valid JSON object. Let me put it this way: you load just one line into memory and get a valid JSON object you can work with in your code. Another line -- another object. Worked with it, released from memory, going next. And this is how you proceed through the entire file, no matter how long it is.

Just imagine a huge JSON array weighting a good couple of huundred MBs. Going straightforward and reading in full would take quite a bunch of memory. Going lined JSON approach would allow you iterating through each line and spending just a little of your precious memory. For sure, in some cases we need the whole thing loaded, but for others it's just fine to go one by one. So, lessons learned, another convenient data structure to use and to handle!

Originally posted in Reading Lined JSON files with Java 8