Re: HttpShardHandlerFactory
Hello Michael, Thank you for pointing that out. Today I am planning to try this out along with the insights Shawn had shared. Thanks! Mark. On Mon, Aug 19, 2019 at 9:21 AM Michael Gibney wrote: > Mark, > > Another thing to check is that I believe the configuration you posted may > not actually be taking effect. Unless I'm mistaken, I think the correct > element name to configure the shardHandler is "shardHandler*Factory*", not > "shardHandler" ... as in, ' class="HttpShardHandlerFactory">...' > > The element name is documented correctly in the refGuide page for "Format > of solr.xml": > > https://lucene.apache.org/solr/guide/8_1/format-of-solr-xml.html#the-shardhandlerfactory-element > > ... but the incorrect (?) element name is included in the refGuide page for > "Distributed Requests": > > https://lucene.apache.org/solr/guide/8_1/distributed-requests.html#configuring-the-shardhandlerfactory > > Michael > > On Fri, Aug 16, 2019 at 9:40 AM Shawn Heisey wrote: > > > On 8/16/2019 3:51 AM, Mark Robinson wrote: > > > I am trying to understand the socket time out and connection time out > in > > > the HttpShardHandlerFactory:- > > > > > > > > >10 > > >20 > > > > > > > The shard handler is used when that Solr instance needs to make > > connections to another Solr instance (which could be itself, as odd as > > that might sound). It does not apply to the requests that you make from > > outside Solr. > > > > > 1.Could some one please help me understand the effect of using such low > > > values of 10 ms > > > and 20ms as given above inside my /select handler? > > > > A connection timeout of 10 milliseconds *might* result in connections > > not establishing at all. This is translated down to the TCP socket as > > the TCP connection timeout -- the time limit imposed on making the TCP > > connection itself. Which as I understand it, is the completion of the > > "SYN", "SYN/ACK", and "ACK" sequence. If the two endpoints of the > > connection are on a LAN, you might never see a problem from this -- LAN > > connections are very low latency. But if they are across the Internet, > > they might never work. > > > > The socket timeout of 20 milliseconds means that if the connection goes > > idle for 20 milliseconds, it will be forcibly closed. So if it took 25 > > milliseconds for the remote Solr instance to respond, this Solr instance > > would have given up and closed the connection. It is extremely common > > for requests to take 100, 500, 2000, or more milliseconds to respond. > > > > > 2. What is the guidelines for setting these parameters? Should they be > > low > > > or high > > > > I would probably use a value of about 5000 (five seconds) for the > > connection timeout if everything's on a local LAN. I might go as high > > as 15 seconds if there's a high latency network between them, but five > > seconds is probably long enough too. > > > > For the socket timeout, you want a value that's considerably longer than > > you expect requests to ever take. Probably somewhere between two and > > five minutes. > > > > > 3. How can I test the effect of this chunk of code after adding it to > my > > > /select handler ie I want to > > > make sure the above code snippet is working. That is why I gave > > such > > > low values and > > > thought when I fire a query I would get both time out errors in > the > > > logs. But did not! > > > Or is it that within the above time frame (10 ms, 20ms) if no > > request > > > comes the socket will > > > time out and the connection will be lost. So to test this should > I > > > give a say 100 TPS load with > > > these low values and then increase the values to maybe 1000 ms > and > > > 1500 ms respectively > > > and see lesser time out error messages? > > > > If you were running a multi-server SolrCloud setup (or a single-server > > setup with multiple shards and/or replicas), you probably would see > > problems from values that low. But if Solr never has any need to make > > connections to satisfy a request, then the values will never take effect. > > > > If you want to control these values for requests made from outside Solr, > > you will need to do it in your client software that is making the > request. > > > > Thanks, > > Shawn > > >
Re: HttpShardHandlerFactory
Hello Shawn, Thank you so much for the detailed response. It was so helpful! Thanks! Mark. On Fri, Aug 16, 2019 at 9:40 AM Shawn Heisey wrote: > On 8/16/2019 3:51 AM, Mark Robinson wrote: > > I am trying to understand the socket time out and connection time out in > > the HttpShardHandlerFactory:- > > > > > >10 > >20 > > > > The shard handler is used when that Solr instance needs to make > connections to another Solr instance (which could be itself, as odd as > that might sound). It does not apply to the requests that you make from > outside Solr. > > > 1.Could some one please help me understand the effect of using such low > > values of 10 ms > > and 20ms as given above inside my /select handler? > > A connection timeout of 10 milliseconds *might* result in connections > not establishing at all. This is translated down to the TCP socket as > the TCP connection timeout -- the time limit imposed on making the TCP > connection itself. Which as I understand it, is the completion of the > "SYN", "SYN/ACK", and "ACK" sequence. If the two endpoints of the > connection are on a LAN, you might never see a problem from this -- LAN > connections are very low latency. But if they are across the Internet, > they might never work. > > The socket timeout of 20 milliseconds means that if the connection goes > idle for 20 milliseconds, it will be forcibly closed. So if it took 25 > milliseconds for the remote Solr instance to respond, this Solr instance > would have given up and closed the connection. It is extremely common > for requests to take 100, 500, 2000, or more milliseconds to respond. > > > 2. What is the guidelines for setting these parameters? Should they be > low > > or high > > I would probably use a value of about 5000 (five seconds) for the > connection timeout if everything's on a local LAN. I might go as high > as 15 seconds if there's a high latency network between them, but five > seconds is probably long enough too. > > For the socket timeout, you want a value that's considerably longer than > you expect requests to ever take. Probably somewhere between two and > five minutes. > > > 3. How can I test the effect of this chunk of code after adding it to my > > /select handler ie I want to > > make sure the above code snippet is working. That is why I gave > such > > low values and > > thought when I fire a query I would get both time out errors in the > > logs. But did not! > > Or is it that within the above time frame (10 ms, 20ms) if no > request > > comes the socket will > > time out and the connection will be lost. So to test this should I > > give a say 100 TPS load with > > these low values and then increase the values to maybe 1000 ms and > > 1500 ms respectively > > and see lesser time out error messages? > > If you were running a multi-server SolrCloud setup (or a single-server > setup with multiple shards and/or replicas), you probably would see > problems from values that low. But if Solr never has any need to make > connections to satisfy a request, then the values will never take effect. > > If you want to control these values for requests made from outside Solr, > you will need to do it in your client software that is making the request. > > Thanks, > Shawn >
Re: HttpShardHandlerFactory
Mark, Another thing to check is that I believe the configuration you posted may not actually be taking effect. Unless I'm mistaken, I think the correct element name to configure the shardHandler is "shardHandler*Factory*", not "shardHandler" ... as in, '...' The element name is documented correctly in the refGuide page for "Format of solr.xml": https://lucene.apache.org/solr/guide/8_1/format-of-solr-xml.html#the-shardhandlerfactory-element ... but the incorrect (?) element name is included in the refGuide page for "Distributed Requests": https://lucene.apache.org/solr/guide/8_1/distributed-requests.html#configuring-the-shardhandlerfactory Michael On Fri, Aug 16, 2019 at 9:40 AM Shawn Heisey wrote: > On 8/16/2019 3:51 AM, Mark Robinson wrote: > > I am trying to understand the socket time out and connection time out in > > the HttpShardHandlerFactory:- > > > > > >10 > >20 > > > > The shard handler is used when that Solr instance needs to make > connections to another Solr instance (which could be itself, as odd as > that might sound). It does not apply to the requests that you make from > outside Solr. > > > 1.Could some one please help me understand the effect of using such low > > values of 10 ms > > and 20ms as given above inside my /select handler? > > A connection timeout of 10 milliseconds *might* result in connections > not establishing at all. This is translated down to the TCP socket as > the TCP connection timeout -- the time limit imposed on making the TCP > connection itself. Which as I understand it, is the completion of the > "SYN", "SYN/ACK", and "ACK" sequence. If the two endpoints of the > connection are on a LAN, you might never see a problem from this -- LAN > connections are very low latency. But if they are across the Internet, > they might never work. > > The socket timeout of 20 milliseconds means that if the connection goes > idle for 20 milliseconds, it will be forcibly closed. So if it took 25 > milliseconds for the remote Solr instance to respond, this Solr instance > would have given up and closed the connection. It is extremely common > for requests to take 100, 500, 2000, or more milliseconds to respond. > > > 2. What is the guidelines for setting these parameters? Should they be > low > > or high > > I would probably use a value of about 5000 (five seconds) for the > connection timeout if everything's on a local LAN. I might go as high > as 15 seconds if there's a high latency network between them, but five > seconds is probably long enough too. > > For the socket timeout, you want a value that's considerably longer than > you expect requests to ever take. Probably somewhere between two and > five minutes. > > > 3. How can I test the effect of this chunk of code after adding it to my > > /select handler ie I want to > > make sure the above code snippet is working. That is why I gave > such > > low values and > > thought when I fire a query I would get both time out errors in the > > logs. But did not! > > Or is it that within the above time frame (10 ms, 20ms) if no > request > > comes the socket will > > time out and the connection will be lost. So to test this should I > > give a say 100 TPS load with > > these low values and then increase the values to maybe 1000 ms and > > 1500 ms respectively > > and see lesser time out error messages? > > If you were running a multi-server SolrCloud setup (or a single-server > setup with multiple shards and/or replicas), you probably would see > problems from values that low. But if Solr never has any need to make > connections to satisfy a request, then the values will never take effect. > > If you want to control these values for requests made from outside Solr, > you will need to do it in your client software that is making the request. > > Thanks, > Shawn >
Re: HttpShardHandlerFactory
On 8/16/2019 3:51 AM, Mark Robinson wrote: I am trying to understand the socket time out and connection time out in the HttpShardHandlerFactory:- 10 20 The shard handler is used when that Solr instance needs to make connections to another Solr instance (which could be itself, as odd as that might sound). It does not apply to the requests that you make from outside Solr. 1.Could some one please help me understand the effect of using such low values of 10 ms and 20ms as given above inside my /select handler? A connection timeout of 10 milliseconds *might* result in connections not establishing at all. This is translated down to the TCP socket as the TCP connection timeout -- the time limit imposed on making the TCP connection itself. Which as I understand it, is the completion of the "SYN", "SYN/ACK", and "ACK" sequence. If the two endpoints of the connection are on a LAN, you might never see a problem from this -- LAN connections are very low latency. But if they are across the Internet, they might never work. The socket timeout of 20 milliseconds means that if the connection goes idle for 20 milliseconds, it will be forcibly closed. So if it took 25 milliseconds for the remote Solr instance to respond, this Solr instance would have given up and closed the connection. It is extremely common for requests to take 100, 500, 2000, or more milliseconds to respond. 2. What is the guidelines for setting these parameters? Should they be low or high I would probably use a value of about 5000 (five seconds) for the connection timeout if everything's on a local LAN. I might go as high as 15 seconds if there's a high latency network between them, but five seconds is probably long enough too. For the socket timeout, you want a value that's considerably longer than you expect requests to ever take. Probably somewhere between two and five minutes. 3. How can I test the effect of this chunk of code after adding it to my /select handler ie I want to make sure the above code snippet is working. That is why I gave such low values and thought when I fire a query I would get both time out errors in the logs. But did not! Or is it that within the above time frame (10 ms, 20ms) if no request comes the socket will time out and the connection will be lost. So to test this should I give a say 100 TPS load with these low values and then increase the values to maybe 1000 ms and 1500 ms respectively and see lesser time out error messages? If you were running a multi-server SolrCloud setup (or a single-server setup with multiple shards and/or replicas), you probably would see problems from values that low. But if Solr never has any need to make connections to satisfy a request, then the values will never take effect. If you want to control these values for requests made from outside Solr, you will need to do it in your client software that is making the request. Thanks, Shawn
HttpShardHandlerFactory
Hello, I am trying to understand the socket time out and connection time out in the HttpShardHandlerFactory:- 10 20 1.Could some one please help me understand the effect of using such low values of 10 ms and 20ms as given above inside my /select handler? 2. What is the guidelines for setting these parameters? Should they be low or high 3. How can I test the effect of this chunk of code after adding it to my /select handler ie I want to make sure the above code snippet is working. That is why I gave such low values and thought when I fire a query I would get both time out errors in the logs. But did not! Or is it that within the above time frame (10 ms, 20ms) if no request comes the socket will time out and the connection will be lost. So to test this should I give a say 100 TPS load with these low values and then increase the values to maybe 1000 ms and 1500 ms respectively and see lesser time out error messages? I am trying to understand how these parameters can be put to good use. Thanks! Mark
