June 2021 - Pharo-users - lists.pharo.org

Re: Communication between different images

by Sven Van Caekenberghe

> On 30 Jun 2021, at 01:28, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > I like the Ansible approach using RabbitMQ, in particular because it > would also work to delegate tasks to workers (even if in the same > image), and the task queue would be preserved, whilst in MQTT if there > are no subscribers for a topic, then all messages sent to it are > discarded. That is correct but less of a problem in practice than it seems to be at first sight. As a client, you normally have to be able to start from scratch and load everything that came before the moment you start up. When a client with a specific ID has connected once with clean session false, QoS 1 and a subscription, the persistence of the queue will be enabled for a as long as the server lives (and maybe even beyond restarts). There is absolutely no question that Rabbit MQ has much more functionality, I found Mosquitto MQTT very nice to work with, but as always, YMMV. Sven

June 30, 2021

Re: Communication between different images

by Sven Van Caekenberghe

> On 29 Jun 2021, at 20:10, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > I already got MQTT running, It's not completely clear to me how the > QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't > remember using that setting in Java (it probably had a sensible > default). >From the comments in MQTTPacket class side atMostOnce "Quality of service level 0 - no acks, send and forget" ^ 0 atLeastOnce "Quality of service level 1 - single acks, possible duplicates" ^ 1 exactlyOnce "Quality of service level 2 - no loss, no duplicates" ^ 2 The lowest one is the fastest, but won't work with persistent queues. In most cases the middle level is OK and enough - duplicates can only occur when you do not receive the ack.

June 30, 2021

Re: Communication between different images

by Esteban Maringolo

Hi Gabriel, I like the Ansible approach using RabbitMQ, in particular because it would also work to delegate tasks to workers (even if in the same image), and the task queue would be preserved, whilst in MQTT if there are no subscribers for a topic, then all messages sent to it are discarded. Is there a way to "start fresh" when subscribing to a queue?, it is, to receive only messages _after_ you subscribed to it? How do you ensure that the publisher/subscriber (and particularly this last) keeps running for the lifetime of an image? It is, what are the failover/recovery options? Regards! Esteban A. Maringolo On Tue, Jun 29, 2021 at 3:44 PM Gabriel Cotelli <g.cotelli(a)gmail.com> wrote: > > If you want to use Rabbit you can also take a look at Ansible for connecting using the protocol instead of STOMP. > > On Tue, Jun 29, 2021 at 3:11 PM Esteban Maringolo <emaringolo(a)gmail.com> wrote: >> >> As far as I understand, ZeroMQ does not require a broker to perform >> the communication between publishers and subscribers, I don't know how >> that is implemented (what do they connect to? how each client >> discovers each other?). >> >> I already got MQTT running, It's not completely clear to me how the >> QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't >> remember using that setting in Java (it probably had a sensible >> default). >> >> Regards! >> >> >> Esteban A. Maringolo >> >> On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre >> <jmariaguirre(a)gmail.com> wrote: >> > >> > Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: >> > >> > Metacello new >> > baseline: 'JupyterTalk'; >> > repository: 'github://jmari/JupyterTalk:master/repository'; >> > load:'zmq' >> > >> > But it needs ZeroMQ previously installed on your system. >> > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... >> > >> > >> > >> > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: >> >> >> >> Hi, >> >> >> >> I'm rearchitecting a web app to perform updates only when necessary >> >> (instead of computing them all the time) on each request, I can have a >> >> global announcer and subscribers to know when to update within an >> >> image, but is there a way to have something like that but for >> >> inter-image coordination? >> >> >> >> I'd only need to communicate the id and the class name (or a similar >> >> identifier), so on other images they'll update accordingly, and if >> >> there is an update in one image, it will notify the other images. The >> >> common data is on the database, so this is just to avoid re-reading a >> >> lot of things. >> >> >> >> Is a message queue a good fit for this? Pub/Sub? >> >> What is available in Pharo that works without having to set up a lot of things? >> >> >> >> Thanks! >> >> >> >> Esteban A. Maringolo

June 29, 2021

Re: Communication between different images

by Gabriel Cotelli

If you want to use Rabbit you can also take a look at Ansible <https://github.com/ba-st/Ansible>for connecting using the protocol instead of STOMP. On Tue, Jun 29, 2021 at 3:11 PM Esteban Maringolo <emaringolo(a)gmail.com> wrote: > As far as I understand, ZeroMQ does not require a broker to perform > the communication between publishers and subscribers, I don't know how > that is implemented (what do they connect to? how each client > discovers each other?). > > I already got MQTT running, It's not completely clear to me how the > QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't > remember using that setting in Java (it probably had a sensible > default). > > Regards! > > > Esteban A. Maringolo > > On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre > <jmariaguirre(a)gmail.com> wrote: > > > > Maybe ZeroMQ fits you, but unlucky is not documented and there are only > a few examples. I use ir in my jupyter kernel. You can install my port to > pharo64 uFFI doing: > > > > Metacello new > > baseline: 'JupyterTalk'; > > repository: 'github://jmari/JupyterTalk:master/repository'; > > load:'zmq' > > > > But it needs ZeroMQ previously installed on your system. > > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is > at: https://github.com/dellani/zeroMQ but I'm not sure if the original > repo works on newer Pharos....I had no time to contact the original author > to join both repos... > > > > > > > > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) > escribiÃ³: > >> > >> Hi, > >> > >> I'm rearchitecting a web app to perform updates only when necessary > >> (instead of computing them all the time) on each request, I can have a > >> global announcer and subscribers to know when to update within an > >> image, but is there a way to have something like that but for > >> inter-image coordination? > >> > >> I'd only need to communicate the id and the class name (or a similar > >> identifier), so on other images they'll update accordingly, and if > >> there is an update in one image, it will notify the other images. The > >> common data is on the database, so this is just to avoid re-reading a > >> lot of things. > >> > >> Is a message queue a good fit for this? Pub/Sub? > >> What is available in Pharo that works without having to set up a lot of > things? > >> > >> Thanks! > >> > >> Esteban A. Maringolo >

June 29, 2021

Re: Communication between different images

by Esteban Maringolo

As far as I understand, ZeroMQ does not require a broker to perform the communication between publishers and subscribers, I don't know how that is implemented (what do they connect to? how each client discovers each other?). I already got MQTT running, It's not completely clear to me how the QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't remember using that setting in Java (it probably had a sensible default). Regards! Esteban A. Maringolo On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre <jmariaguirre(a)gmail.com> wrote: > > Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: > > Metacello new > baseline: 'JupyterTalk'; > repository: 'github://jmari/JupyterTalk:master/repository'; > load:'zmq' > > But it needs ZeroMQ previously installed on your system. > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... > > > > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: >> >> Hi, >> >> I'm rearchitecting a web app to perform updates only when necessary >> (instead of computing them all the time) on each request, I can have a >> global announcer and subscribers to know when to update within an >> image, but is there a way to have something like that but for >> inter-image coordination? >> >> I'd only need to communicate the id and the class name (or a similar >> identifier), so on other images they'll update accordingly, and if >> there is an update in one image, it will notify the other images. The >> common data is on the database, so this is just to avoid re-reading a >> lot of things. >> >> Is a message queue a good fit for this? Pub/Sub? >> What is available in Pharo that works without having to set up a lot of things? >> >> Thanks! >> >> Esteban A. Maringolo

June 29, 2021

Re: Communication between different images

by Jesus Mari Aguirre

Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: Metacello new baseline: 'JupyterTalk'; repository: 'github://jmari/JupyterTalk:master/repository'; load:'zmq' But it needs ZeroMQ previously installed on your system. It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: > Hi, > > I'm rearchitecting a web app to perform updates only when necessary > (instead of computing them all the time) on each request, I can have a > global announcer and subscribers to know when to update within an > image, but is there a way to have something like that but for > inter-image coordination? > > I'd only need to communicate the id and the class name (or a similar > identifier), so on other images they'll update accordingly, and if > there is an update in one image, it will notify the other images. The > common data is on the database, so this is just to avoid re-reading a > lot of things. > > Is a message queue a good fit for this? Pub/Sub? > What is available in Pharo that works without having to set up a lot of > things? > > Thanks! > > Esteban A. Maringolo >

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Sebastian Jordan

No problem Steffen. Have a nice day too! Sebastian ________________________________ De : Steffen MÃ¤rcker <merkste(a)web.de> EnvoyÃ© : mardi 29 juin 2021 Ã 18:27 Ã : Any question about pharo is welcome Objet : [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Thanks Sebastian, that's exactly what I was looking for. I vaguely remembered that such a site exits. =) Have a nice day! Steffen Sebastian Jordan schrieb am Dienstag, 29. Juni 2021 18:23:23 (+02:00): Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com…> Sebastian ________________________________ From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter. -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Steffen MÃ¤rcker

Thanks Sebastian, that's exactly what I was looking for. I vaguely remembered that such a site exits. =) Have a nice day! Steffen Sebastian Jordan schrieb am Dienstag, 29. Juni 2021 18:23:23 (+02:00): Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo Sebastian From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter. -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Sebastian Jordan

Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo Sebastian ________________________________ From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Steffen MÃ¤rcker

Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021